Re-engineering of terminal emulator, phase 1.

[u/mdw/putty] / unix / pterm.c

/*
 * pterm - a fusion of the PuTTY terminal emulator with a Unix pty
 * back end, all running as a GTK application. Wish me luck.
 */

#define _GNU_SOURCE

#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <gtk/gtk.h>
#include <gdk/gdkkeysyms.h>
#include <gdk/gdkx.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xatom.h>

#define PUTTY_DO_GLOBALS               /* actually _define_ globals */

#include "putty.h"
#include "terminal.h"

#define CAT2(x,y) x ## y
#define CAT(x,y) CAT2(x,y)
#define ASSERT(x) enum {CAT(assertion_,__LINE__) = 1 / (x)}

#define NCOLOURS (lenof(((Config *)0)->colours))

GdkAtom compound_text_atom, utf8_string_atom;

extern char **pty_argv;        /* declared in pty.c */
extern int use_pty_argv;

struct gui_data {
    GtkWidget *window, *area, *sbar;
    GtkBox *hbox;
    GtkAdjustment *sbar_adjust;
    GtkWidget *menu, *specialsmenu, *specialsitem1, *specialsitem2,
        *restartitem;
    GtkWidget *sessionsmenu;
    GdkPixmap *pixmap;
    GdkFont *fonts[4];                 /* normal, bold, wide, widebold */
    struct {
        int charset;
        int is_wide;
    } fontinfo[4];
    int xpos, ypos, gotpos, gravity;
    GdkCursor *rawcursor, *textcursor, *blankcursor, *currcursor;
    GdkColor cols[NCOLOURS];
    GdkColormap *colmap;
    wchar_t *pastein_data;
    int direct_to_font;
    int pastein_data_len;
    char *pasteout_data, *pasteout_data_ctext, *pasteout_data_utf8;
    int pasteout_data_len, pasteout_data_ctext_len, pasteout_data_utf8_len;
    int font_width, font_height;
    int width, height;
    int ignore_sbar;
    int mouseptr_visible;
    guint term_paste_idle_id;
    int alt_keycode;
    int alt_digits;
    char wintitle[sizeof(((Config *)0)->wintitle)];
    char icontitle[sizeof(((Config *)0)->wintitle)];
    int master_fd, master_func_id;
    void *ldisc;
    Backend *back;
    void *backhandle;
    Terminal *term;
    void *logctx;
    int exited;
    struct unicode_data ucsdata;
    Config cfg;
    void *eventlogstuff;
    char *progname, **gtkargvstart;
    int ngtkargs;
    guint32 input_event_time; /* Timestamp of the most recent input event. */
};

struct draw_ctx {
    GdkGC *gc;
    struct gui_data *inst;
};

static int send_raw_mouse;

static char *app_name = "pterm";

static void start_backend(struct gui_data *inst);

char *x_get_default(const char *key)
{
    return XGetDefault(GDK_DISPLAY(), app_name, key);
}

void connection_fatal(void *frontend, char *p, ...)
{
    struct gui_data *inst = (struct gui_data *)frontend;

    va_list ap;
    char *msg;
    va_start(ap, p);
    msg = dupvprintf(p, ap);
    va_end(ap);
    inst->exited = TRUE;
    fatal_message_box(inst->window, msg);
    sfree(msg);
    if (inst->cfg.close_on_exit == FORCE_ON)
        cleanup_exit(1);
}

/*
 * Default settings that are specific to pterm.
 */
FontSpec platform_default_fontspec(const char *name)
{
    FontSpec ret;
    if (!strcmp(name, "Font"))
        strcpy(ret.name, "fixed");
    else
        *ret.name = '\0';
    return ret;
}

Filename platform_default_filename(const char *name)
{
    Filename ret;
    if (!strcmp(name, "LogFileName"))
        strcpy(ret.path, "putty.log");
    else
        *ret.path = '\0';
    return ret;
}

char *platform_default_s(const char *name)
{
    return NULL;
}

int platform_default_i(const char *name, int def)
{
    if (!strcmp(name, "CloseOnExit"))
        return 2;  /* maps to FORCE_ON after painful rearrangement :-( */
    if (!strcmp(name, "WinNameAlways"))
        return 0;  /* X natively supports icon titles, so use 'em by default */
    return def;
}

void ldisc_update(void *frontend, int echo, int edit)
{
    /*
     * This is a stub in pterm. If I ever produce a Unix
     * command-line ssh/telnet/rlogin client (i.e. a port of plink)
     * then it will require some termios manoeuvring analogous to
     * that in the Windows plink.c, but here it's meaningless.
     */
}

int from_backend(void *frontend, int is_stderr, const char *data, int len)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    return term_data(inst->term, is_stderr, data, len);
}

void logevent(void *frontend, const char *string)
{
    struct gui_data *inst = (struct gui_data *)frontend;

    log_eventlog(inst->logctx, string);

    logevent_dlg(inst->eventlogstuff, string);
}

int font_dimension(void *frontend, int which)/* 0 for width, 1 for height */
{
    struct gui_data *inst = (struct gui_data *)frontend;

    if (which)
        return inst->font_height;
    else
        return inst->font_width;
}

/*
 * Translate a raw mouse button designation (LEFT, MIDDLE, RIGHT)
 * into a cooked one (SELECT, EXTEND, PASTE).
 * 
 * In Unix, this is not configurable; the X button arrangement is
 * rock-solid across all applications, everyone has a three-button
 * mouse or a means of faking it, and there is no need to switch
 * buttons around at all.
 */
static Mouse_Button translate_button(Mouse_Button button)
{
    /* struct gui_data *inst = (struct gui_data *)frontend; */

    if (button == MBT_LEFT)
        return MBT_SELECT;
    if (button == MBT_MIDDLE)
        return MBT_PASTE;
    if (button == MBT_RIGHT)
        return MBT_EXTEND;
    return 0;                          /* shouldn't happen */
}

/*
 * Return the top-level GtkWindow associated with a particular
 * front end instance.
 */
void *get_window(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    return inst->window;
}

/*
 * Minimise or restore the window in response to a server-side
 * request.
 */
void set_iconic(void *frontend, int iconic)
{
    /*
     * GTK 1.2 doesn't know how to do this.
     */
#if GTK_CHECK_VERSION(2,0,0)
    struct gui_data *inst = (struct gui_data *)frontend;
    if (iconic)
        gtk_window_iconify(GTK_WINDOW(inst->window));
    else
        gtk_window_deiconify(GTK_WINDOW(inst->window));
#endif
}

/*
 * Move the window in response to a server-side request.
 */
void move_window(void *frontend, int x, int y)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    /*
     * I assume that when the GTK version of this call is available
     * we should use it. Not sure how it differs from the GDK one,
     * though.
     */
#if GTK_CHECK_VERSION(2,0,0)
    gtk_window_move(GTK_WINDOW(inst->window), x, y);
#else
    gdk_window_move(inst->window->window, x, y);
#endif
}

/*
 * Move the window to the top or bottom of the z-order in response
 * to a server-side request.
 */
void set_zorder(void *frontend, int top)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    if (top)
        gdk_window_raise(inst->window->window);
    else
        gdk_window_lower(inst->window->window);
}

/*
 * Refresh the window in response to a server-side request.
 */
void refresh_window(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    term_invalidate(inst->term);
}

/*
 * Maximise or restore the window in response to a server-side
 * request.
 */
void set_zoomed(void *frontend, int zoomed)
{
    /*
     * GTK 1.2 doesn't know how to do this.
     */
#if GTK_CHECK_VERSION(2,0,0)
    struct gui_data *inst = (struct gui_data *)frontend;
    if (iconic)
        gtk_window_maximize(GTK_WINDOW(inst->window));
    else
        gtk_window_unmaximize(GTK_WINDOW(inst->window));
#endif
}

/*
 * Report whether the window is iconic, for terminal reports.
 */
int is_iconic(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    return !gdk_window_is_viewable(inst->window->window);
}

/*
 * Report the window's position, for terminal reports.
 */
void get_window_pos(void *frontend, int *x, int *y)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    /*
     * I assume that when the GTK version of this call is available
     * we should use it. Not sure how it differs from the GDK one,
     * though.
     */
#if GTK_CHECK_VERSION(2,0,0)
    gtk_window_get_position(GTK_WINDOW(inst->window), x, y);
#else
    gdk_window_get_position(inst->window->window, x, y);
#endif
}

/*
 * Report the window's pixel size, for terminal reports.
 */
void get_window_pixels(void *frontend, int *x, int *y)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    /*
     * I assume that when the GTK version of this call is available
     * we should use it. Not sure how it differs from the GDK one,
     * though.
     */
#if GTK_CHECK_VERSION(2,0,0)
    gtk_window_get_size(GTK_WINDOW(inst->window), x, y);
#else
    gdk_window_get_size(inst->window->window, x, y);
#endif
}

/*
 * Return the window or icon title.
 */
char *get_window_title(void *frontend, int icon)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    return icon ? inst->icontitle : inst->wintitle;
}

gint delete_window(GtkWidget *widget, GdkEvent *event, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    if (!inst->exited && inst->cfg.warn_on_close) {
        if (!reallyclose(inst))
            return TRUE;
    }
    return FALSE;
}

static void show_mouseptr(struct gui_data *inst, int show)
{
    if (!inst->cfg.hide_mouseptr)
        show = 1;
    if (show)
        gdk_window_set_cursor(inst->area->window, inst->currcursor);
    else
        gdk_window_set_cursor(inst->area->window, inst->blankcursor);
    inst->mouseptr_visible = show;
}

void draw_backing_rect(struct gui_data *inst)
{
    GdkGC *gc = gdk_gc_new(inst->area->window);
    gdk_gc_set_foreground(gc, &inst->cols[18]);   /* default background */
    gdk_draw_rectangle(inst->pixmap, gc, 1, 0, 0,
                       inst->cfg.width * inst->font_width + 2*inst->cfg.window_border,
                       inst->cfg.height * inst->font_height + 2*inst->cfg.window_border);
    gdk_gc_unref(gc);
}

gint configure_area(GtkWidget *widget, GdkEventConfigure *event, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    int w, h, need_size = 0;

    /*
     * See if the terminal size has changed, in which case we must
     * let the terminal know.
     */
    w = (event->width - 2*inst->cfg.window_border) / inst->font_width;
    h = (event->height - 2*inst->cfg.window_border) / inst->font_height;
    if (w != inst->width || h != inst->height) {
        inst->cfg.width = inst->width = w;
        inst->cfg.height = inst->height = h;
        need_size = 1;
    }

    if (inst->pixmap) {
        gdk_pixmap_unref(inst->pixmap);
        inst->pixmap = NULL;
    }

    inst->pixmap = gdk_pixmap_new(widget->window,
                                  (inst->cfg.width * inst->font_width +
                                   2*inst->cfg.window_border),
                                  (inst->cfg.height * inst->font_height +
                                   2*inst->cfg.window_border), -1);

    draw_backing_rect(inst);

    if (need_size && inst->term) {
        term_size(inst->term, h, w, inst->cfg.savelines);
    }

    if (inst->term)
        term_invalidate(inst->term);

    return TRUE;
}

gint expose_area(GtkWidget *widget, GdkEventExpose *event, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;

    /*
     * Pass the exposed rectangle to terminal.c, which will call us
     * back to do the actual painting.
     */
    if (inst->pixmap) {
        gdk_draw_pixmap(widget->window,
                        widget->style->fg_gc[GTK_WIDGET_STATE(widget)],
                        inst->pixmap,
                        event->area.x, event->area.y,
                        event->area.x, event->area.y,
                        event->area.width, event->area.height);
    }
    return TRUE;
}

#define KEY_PRESSED(k) \
    (inst->keystate[(k) / 32] & (1 << ((k) % 32)))

gint key_event(GtkWidget *widget, GdkEventKey *event, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    char output[32];
    wchar_t ucsoutput[2];
    int ucsval, start, end, special, use_ucsoutput;

    /* Remember the timestamp. */
    inst->input_event_time = event->time;

    /* By default, nothing is generated. */
    end = start = 0;
    special = use_ucsoutput = FALSE;

    /*
     * If Alt is being released after typing an Alt+numberpad
     * sequence, we should generate the code that was typed.
     * 
     * Note that we only do this if more than one key was actually
     * pressed - I don't think Alt+NumPad4 should be ^D or that
     * Alt+NumPad3 should be ^C, for example. There's no serious
     * inconvenience in having to type a zero before a single-digit
     * character code.
     */
    if (event->type == GDK_KEY_RELEASE &&
        (event->keyval == GDK_Meta_L || event->keyval == GDK_Alt_L ||
         event->keyval == GDK_Meta_R || event->keyval == GDK_Alt_R) &&
        inst->alt_keycode >= 0 && inst->alt_digits > 1) {
#ifdef KEY_DEBUGGING
        printf("Alt key up, keycode = %d\n", inst->alt_keycode);
#endif
        output[0] = inst->alt_keycode;
        end = 1;
        goto done;
    }

    if (event->type == GDK_KEY_PRESS) {
#ifdef KEY_DEBUGGING
        {
            int i;
            printf("keypress: keyval = %04x, state = %08x; string =",
                   event->keyval, event->state);
            for (i = 0; event->string[i]; i++)
                printf(" %02x", (unsigned char) event->string[i]);
            printf("\n");
        }
#endif

        /*
         * NYI: Compose key (!!! requires Unicode faff before even trying)
         */

        /*
         * If Alt has just been pressed, we start potentially
         * accumulating an Alt+numberpad code. We do this by
         * setting alt_keycode to -1 (nothing yet but plausible).
         */
        if ((event->keyval == GDK_Meta_L || event->keyval == GDK_Alt_L ||
             event->keyval == GDK_Meta_R || event->keyval == GDK_Alt_R)) {
            inst->alt_keycode = -1;
            inst->alt_digits = 0;
            goto done;                 /* this generates nothing else */
        }

        /*
         * If we're seeing a numberpad key press with Mod1 down,
         * consider adding it to alt_keycode if that's sensible.
         * Anything _else_ with Mod1 down cancels any possibility
         * of an ALT keycode: we set alt_keycode to -2.
         */
        if ((event->state & GDK_MOD1_MASK) && inst->alt_keycode != -2) {
            int digit = -1;
            switch (event->keyval) {
              case GDK_KP_0: case GDK_KP_Insert: digit = 0; break;
              case GDK_KP_1: case GDK_KP_End: digit = 1; break;
              case GDK_KP_2: case GDK_KP_Down: digit = 2; break;
              case GDK_KP_3: case GDK_KP_Page_Down: digit = 3; break;
              case GDK_KP_4: case GDK_KP_Left: digit = 4; break;
              case GDK_KP_5: case GDK_KP_Begin: digit = 5; break;
              case GDK_KP_6: case GDK_KP_Right: digit = 6; break;
              case GDK_KP_7: case GDK_KP_Home: digit = 7; break;
              case GDK_KP_8: case GDK_KP_Up: digit = 8; break;
              case GDK_KP_9: case GDK_KP_Page_Up: digit = 9; break;
            }
            if (digit < 0)
                inst->alt_keycode = -2;   /* it's invalid */
            else {
#ifdef KEY_DEBUGGING
                printf("Adding digit %d to keycode %d", digit,
                       inst->alt_keycode);
#endif
                if (inst->alt_keycode == -1)
                    inst->alt_keycode = digit;   /* one-digit code */
                else
                    inst->alt_keycode = inst->alt_keycode * 10 + digit;
                inst->alt_digits++;
#ifdef KEY_DEBUGGING
                printf(" gives new code %d\n", inst->alt_keycode);
#endif
                /* Having used this digit, we now do nothing more with it. */
                goto done;
            }
        }

        /*
         * Shift-PgUp and Shift-PgDn don't even generate keystrokes
         * at all.
         */
        if (event->keyval == GDK_Page_Up && (event->state & GDK_SHIFT_MASK)) {
            term_scroll(inst->term, 0, -inst->cfg.height/2);
            return TRUE;
        }
        if (event->keyval == GDK_Page_Up && (event->state & GDK_CONTROL_MASK)) {
            term_scroll(inst->term, 0, -1);
            return TRUE;
        }
        if (event->keyval == GDK_Page_Down && (event->state & GDK_SHIFT_MASK)) {
            term_scroll(inst->term, 0, +inst->cfg.height/2);
            return TRUE;
        }
        if (event->keyval == GDK_Page_Down && (event->state & GDK_CONTROL_MASK)) {
            term_scroll(inst->term, 0, +1);
            return TRUE;
        }

        /*
         * Neither does Shift-Ins.
         */
        if (event->keyval == GDK_Insert && (event->state & GDK_SHIFT_MASK)) {
            request_paste(inst);
            return TRUE;
        }

        special = FALSE;
        use_ucsoutput = FALSE;

        /* ALT+things gives leading Escape. */
        output[0] = '\033';
        strncpy(output+1, event->string, 31);
        if (!*event->string &&
            (ucsval = keysym_to_unicode(event->keyval)) >= 0) {
            ucsoutput[0] = '\033';
            ucsoutput[1] = ucsval;
            use_ucsoutput = TRUE;
            end = 2;
        } else {
            output[31] = '\0';
            end = strlen(output);
        }
        if (event->state & GDK_MOD1_MASK) {
            start = 0;
            if (end == 1) end = 0;
        } else
            start = 1;

        /* Control-` is the same as Control-\ (unless gtk has a better idea) */
        if (!event->string[0] && event->keyval == '`' &&
            (event->state & GDK_CONTROL_MASK)) {
            output[1] = '\x1C';
            use_ucsoutput = FALSE;
            end = 2;
        }

        /* Control-Break is the same as Control-C */
        if (event->keyval == GDK_Break &&
            (event->state & GDK_CONTROL_MASK)) {
            output[1] = '\003';
            use_ucsoutput = FALSE;
            end = 2;
            special = TRUE;
        }

        /* We handle Return ourselves, because it needs to be flagged as
         * special to ldisc. */
        if (event->keyval == GDK_Return) {
            output[1] = '\015';
            use_ucsoutput = FALSE;
            end = 2;
            special = TRUE;
        }

        /* Control-2, Control-Space and Control-@ are NUL */
        if (!event->string[0] &&
            (event->keyval == ' ' || event->keyval == '2' ||
             event->keyval == '@') &&
            (event->state & (GDK_SHIFT_MASK |
                             GDK_CONTROL_MASK)) == GDK_CONTROL_MASK) {
            output[1] = '\0';
            use_ucsoutput = FALSE;
            end = 2;
        }

        /* Control-Shift-Space is 160 (ISO8859 nonbreaking space) */
        if (!event->string[0] && event->keyval == ' ' &&
            (event->state & (GDK_SHIFT_MASK | GDK_CONTROL_MASK)) ==
            (GDK_SHIFT_MASK | GDK_CONTROL_MASK)) {
            output[1] = '\240';
            use_ucsoutput = FALSE;
            end = 2;
        }

        /* We don't let GTK tell us what Backspace is! We know better. */
        if (event->keyval == GDK_BackSpace &&
            !(event->state & GDK_SHIFT_MASK)) {
            output[1] = inst->cfg.bksp_is_delete ? '\x7F' : '\x08';
            use_ucsoutput = FALSE;
            end = 2;
            special = TRUE;
        }
        /* For Shift Backspace, do opposite of what is configured. */
        if (event->keyval == GDK_BackSpace &&
            (event->state & GDK_SHIFT_MASK)) {
            output[1] = inst->cfg.bksp_is_delete ? '\x08' : '\x7F';
            use_ucsoutput = FALSE;
            end = 2;
            special = TRUE;
        }

        /* Shift-Tab is ESC [ Z */
        if (event->keyval == GDK_ISO_Left_Tab ||
            (event->keyval == GDK_Tab && (event->state & GDK_SHIFT_MASK))) {
            end = 1 + sprintf(output+1, "\033[Z");
            use_ucsoutput = FALSE;
        }

        /*
         * NetHack keypad mode.
         */
        if (inst->cfg.nethack_keypad) {
            char *keys = NULL;
            switch (event->keyval) {
              case GDK_KP_1: case GDK_KP_End: keys = "bB"; break;
              case GDK_KP_2: case GDK_KP_Down: keys = "jJ"; break;
              case GDK_KP_3: case GDK_KP_Page_Down: keys = "nN"; break;
              case GDK_KP_4: case GDK_KP_Left: keys = "hH"; break;
              case GDK_KP_5: case GDK_KP_Begin: keys = ".."; break;
              case GDK_KP_6: case GDK_KP_Right: keys = "lL"; break;
              case GDK_KP_7: case GDK_KP_Home: keys = "yY"; break;
              case GDK_KP_8: case GDK_KP_Up: keys = "kK"; break;
              case GDK_KP_9: case GDK_KP_Page_Up: keys = "uU"; break;
            }
            if (keys) {
                end = 2;
                if (event->state & GDK_SHIFT_MASK)
                    output[1] = keys[1];
                else
                    output[1] = keys[0];
                use_ucsoutput = FALSE;
                goto done;
            }
        }

        /*
         * Application keypad mode.
         */
        if (inst->term->app_keypad_keys && !inst->cfg.no_applic_k) {
            int xkey = 0;
            switch (event->keyval) {
              case GDK_Num_Lock: xkey = 'P'; break;
              case GDK_KP_Divide: xkey = 'Q'; break;
              case GDK_KP_Multiply: xkey = 'R'; break;
              case GDK_KP_Subtract: xkey = 'S'; break;
                /*
                 * Keypad + is tricky. It covers a space that would
                 * be taken up on the VT100 by _two_ keys; so we
                 * let Shift select between the two. Worse still,
                 * in xterm function key mode we change which two...
                 */
              case GDK_KP_Add:
                if (inst->cfg.funky_type == FUNKY_XTERM) {
                    if (event->state & GDK_SHIFT_MASK)
                        xkey = 'l';
                    else
                        xkey = 'k';
                } else if (event->state & GDK_SHIFT_MASK)
                        xkey = 'm';
                else
                    xkey = 'l';
                break;
              case GDK_KP_Enter: xkey = 'M'; break;
              case GDK_KP_0: case GDK_KP_Insert: xkey = 'p'; break;
              case GDK_KP_1: case GDK_KP_End: xkey = 'q'; break;
              case GDK_KP_2: case GDK_KP_Down: xkey = 'r'; break;
              case GDK_KP_3: case GDK_KP_Page_Down: xkey = 's'; break;
              case GDK_KP_4: case GDK_KP_Left: xkey = 't'; break;
              case GDK_KP_5: case GDK_KP_Begin: xkey = 'u'; break;
              case GDK_KP_6: case GDK_KP_Right: xkey = 'v'; break;
              case GDK_KP_7: case GDK_KP_Home: xkey = 'w'; break;
              case GDK_KP_8: case GDK_KP_Up: xkey = 'x'; break;
              case GDK_KP_9: case GDK_KP_Page_Up: xkey = 'y'; break;
              case GDK_KP_Decimal: case GDK_KP_Delete: xkey = 'n'; break;
            }
            if (xkey) {
                if (inst->term->vt52_mode) {
                    if (xkey >= 'P' && xkey <= 'S')
                        end = 1 + sprintf(output+1, "\033%c", xkey);
                    else
                        end = 1 + sprintf(output+1, "\033?%c", xkey);
                } else
                    end = 1 + sprintf(output+1, "\033O%c", xkey);
                use_ucsoutput = FALSE;
                goto done;
            }
        }

        /*
         * Next, all the keys that do tilde codes. (ESC '[' nn '~',
         * for integer decimal nn.)
         *
         * We also deal with the weird ones here. Linux VCs replace F1
         * to F5 by ESC [ [ A to ESC [ [ E. rxvt doesn't do _that_, but
         * does replace Home and End (1~ and 4~) by ESC [ H and ESC O w
         * respectively.
         */
        {
            int code = 0;
            switch (event->keyval) {
              case GDK_F1:
                code = (event->state & GDK_SHIFT_MASK ? 23 : 11);
                break;
              case GDK_F2:
                code = (event->state & GDK_SHIFT_MASK ? 24 : 12);
                break;
              case GDK_F3:
                code = (event->state & GDK_SHIFT_MASK ? 25 : 13);
                break;
              case GDK_F4:
                code = (event->state & GDK_SHIFT_MASK ? 26 : 14);
                break;
              case GDK_F5:
                code = (event->state & GDK_SHIFT_MASK ? 28 : 15);
                break;
              case GDK_F6:
                code = (event->state & GDK_SHIFT_MASK ? 29 : 17);
                break;
              case GDK_F7:
                code = (event->state & GDK_SHIFT_MASK ? 31 : 18);
                break;
              case GDK_F8:
                code = (event->state & GDK_SHIFT_MASK ? 32 : 19);
                break;
              case GDK_F9:
                code = (event->state & GDK_SHIFT_MASK ? 33 : 20);
                break;
              case GDK_F10:
                code = (event->state & GDK_SHIFT_MASK ? 34 : 21);
                break;
              case GDK_F11:
                code = 23;
                break;
              case GDK_F12:
                code = 24;
                break;
              case GDK_F13:
                code = 25;
                break;
              case GDK_F14:
                code = 26;
                break;
              case GDK_F15:
                code = 28;
                break;
              case GDK_F16:
                code = 29;
                break;
              case GDK_F17:
                code = 31;
                break;
              case GDK_F18:
                code = 32;
                break;
              case GDK_F19:
                code = 33;
                break;
              case GDK_F20:
                code = 34;
                break;
            }
            if (!(event->state & GDK_CONTROL_MASK)) switch (event->keyval) {
              case GDK_Home: case GDK_KP_Home:
                code = 1;
                break;
              case GDK_Insert: case GDK_KP_Insert:
                code = 2;
                break;
              case GDK_Delete: case GDK_KP_Delete:
                code = 3;
                break;
              case GDK_End: case GDK_KP_End:
                code = 4;
                break;
              case GDK_Page_Up: case GDK_KP_Page_Up:
                code = 5;
                break;
              case GDK_Page_Down: case GDK_KP_Page_Down:
                code = 6;
                break;
            }
            /* Reorder edit keys to physical order */
            if (inst->cfg.funky_type == FUNKY_VT400 && code <= 6)
                code = "\0\2\1\4\5\3\6"[code];

            if (inst->term->vt52_mode && code > 0 && code <= 6) {
                end = 1 + sprintf(output+1, "\x1B%c", " HLMEIG"[code]);
                use_ucsoutput = FALSE;
                goto done;
            }

            if (inst->cfg.funky_type == FUNKY_SCO &&     /* SCO function keys */
                code >= 11 && code <= 34) {
                char codes[] = "MNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz@[\\]^_`{";
                int index = 0;
                switch (event->keyval) {
                  case GDK_F1: index = 0; break;
                  case GDK_F2: index = 1; break;
                  case GDK_F3: index = 2; break;
                  case GDK_F4: index = 3; break;
                  case GDK_F5: index = 4; break;
                  case GDK_F6: index = 5; break;
                  case GDK_F7: index = 6; break;
                  case GDK_F8: index = 7; break;
                  case GDK_F9: index = 8; break;
                  case GDK_F10: index = 9; break;
                  case GDK_F11: index = 10; break;
                  case GDK_F12: index = 11; break;
                }
                if (event->state & GDK_SHIFT_MASK) index += 12;
                if (event->state & GDK_CONTROL_MASK) index += 24;
                end = 1 + sprintf(output+1, "\x1B[%c", codes[index]);
                use_ucsoutput = FALSE;
                goto done;
            }
            if (inst->cfg.funky_type == FUNKY_SCO &&     /* SCO small keypad */
                code >= 1 && code <= 6) {
                char codes[] = "HL.FIG";
                if (code == 3) {
                    output[1] = '\x7F';
                    end = 2;
                } else {
                    end = 1 + sprintf(output+1, "\x1B[%c", codes[code-1]);
                }
                use_ucsoutput = FALSE;
                goto done;
            }
            if ((inst->term->vt52_mode || inst->cfg.funky_type == FUNKY_VT100P) &&
                code >= 11 && code <= 24) {
                int offt = 0;
                if (code > 15)
                    offt++;
                if (code > 21)
                    offt++;
                if (inst->term->vt52_mode)
                    end = 1 + sprintf(output+1,
                                      "\x1B%c", code + 'P' - 11 - offt);
                else
                    end = 1 + sprintf(output+1,
                                      "\x1BO%c", code + 'P' - 11 - offt);
                use_ucsoutput = FALSE;
                goto done;
            }
            if (inst->cfg.funky_type == FUNKY_LINUX && code >= 11 && code <= 15) {
                end = 1 + sprintf(output+1, "\x1B[[%c", code + 'A' - 11);
                use_ucsoutput = FALSE;
                goto done;
            }
            if (inst->cfg.funky_type == FUNKY_XTERM && code >= 11 && code <= 14) {
                if (inst->term->vt52_mode)
                    end = 1 + sprintf(output+1, "\x1B%c", code + 'P' - 11);
                else
                    end = 1 + sprintf(output+1, "\x1BO%c", code + 'P' - 11);
                use_ucsoutput = FALSE;
                goto done;
            }
            if (inst->cfg.rxvt_homeend && (code == 1 || code == 4)) {
                end = 1 + sprintf(output+1, code == 1 ? "\x1B[H" : "\x1BOw");
                use_ucsoutput = FALSE;
                goto done;
            }
            if (code) {
                end = 1 + sprintf(output+1, "\x1B[%d~", code);
                use_ucsoutput = FALSE;
                goto done;
            }
        }

        /*
         * Cursor keys. (This includes the numberpad cursor keys,
         * if we haven't already done them due to app keypad mode.)
         * 
         * Here we also process un-numlocked un-appkeypadded KP5,
         * which sends ESC [ G.
         */
        {
            int xkey = 0;
            switch (event->keyval) {
              case GDK_Up: case GDK_KP_Up: xkey = 'A'; break;
              case GDK_Down: case GDK_KP_Down: xkey = 'B'; break;
              case GDK_Right: case GDK_KP_Right: xkey = 'C'; break;
              case GDK_Left: case GDK_KP_Left: xkey = 'D'; break;
              case GDK_Begin: case GDK_KP_Begin: xkey = 'G'; break;
            }
            if (xkey) {
                /*
                 * The arrow keys normally do ESC [ A and so on. In
                 * app cursor keys mode they do ESC O A instead.
                 * Ctrl toggles the two modes.
                 */
                if (inst->term->vt52_mode) {
                    end = 1 + sprintf(output+1, "\033%c", xkey);
                } else if (!inst->term->app_cursor_keys ^
                           !(event->state & GDK_CONTROL_MASK)) {
                    end = 1 + sprintf(output+1, "\033O%c", xkey);
                } else {                    
                    end = 1 + sprintf(output+1, "\033[%c", xkey);
                }
                use_ucsoutput = FALSE;
                goto done;
            }
        }
        goto done;
    }

    done:

    if (end-start > 0) {
#ifdef KEY_DEBUGGING
        int i;
        printf("generating sequence:");
        for (i = start; i < end; i++)
            printf(" %02x", (unsigned char) output[i]);
        printf("\n");
#endif

        if (special) {
            /*
             * For special control characters, the character set
             * should never matter.
             */
            output[end] = '\0';        /* NUL-terminate */
            if (inst->ldisc)
                ldisc_send(inst->ldisc, output+start, -2, 1);
        } else if (!inst->direct_to_font) {
            if (!use_ucsoutput) {
                /*
                 * The stuff we've just generated is assumed to be
                 * ISO-8859-1! This sounds insane, but `man
                 * XLookupString' agrees: strings of this type
                 * returned from the X server are hardcoded to
                 * 8859-1. Strictly speaking we should be doing
                 * this using some sort of GtkIMContext, which (if
                 * we're lucky) would give us our data directly in
                 * Unicode; but that's not supported in GTK 1.2 as
                 * far as I can tell, and it's poorly documented
                 * even in 2.0, so it'll have to wait.
                 */
                if (inst->ldisc)
                    lpage_send(inst->ldisc, CS_ISO8859_1, output+start,
                               end-start, 1);
            } else {
                /*
                 * We generated our own Unicode key data from the
                 * keysym, so use that instead.
                 */
                if (inst->ldisc)
                    luni_send(inst->ldisc, ucsoutput+start, end-start, 1);
            }
        } else {
            /*
             * In direct-to-font mode, we just send the string
             * exactly as we received it.
             */
            if (inst->ldisc)
                ldisc_send(inst->ldisc, output+start, end-start, 1);
        }

        show_mouseptr(inst, 0);
        term_seen_key_event(inst->term);
        term_out(inst->term);
    }

    return TRUE;
}

gint button_event(GtkWidget *widget, GdkEventButton *event, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    int shift, ctrl, alt, x, y, button, act;

    /* Remember the timestamp. */
    inst->input_event_time = event->time;

    show_mouseptr(inst, 1);

    if (event->button == 4 && event->type == GDK_BUTTON_PRESS) {
        term_scroll(inst->term, 0, -5);
        return TRUE;
    }
    if (event->button == 5 && event->type == GDK_BUTTON_PRESS) {
        term_scroll(inst->term, 0, +5);
        return TRUE;
    }

    shift = event->state & GDK_SHIFT_MASK;
    ctrl = event->state & GDK_CONTROL_MASK;
    alt = event->state & GDK_MOD1_MASK;

    if (event->button == 3 && ctrl) {
        gtk_menu_popup(GTK_MENU(inst->menu), NULL, NULL, NULL, NULL,
                       event->button, event->time);
        return TRUE;
    }

    if (event->button == 1)
        button = MBT_LEFT;
    else if (event->button == 2)
        button = MBT_MIDDLE;
    else if (event->button == 3)
        button = MBT_RIGHT;
    else
        return FALSE;                  /* don't even know what button! */

    switch (event->type) {
      case GDK_BUTTON_PRESS: act = MA_CLICK; break;
      case GDK_BUTTON_RELEASE: act = MA_RELEASE; break;
      case GDK_2BUTTON_PRESS: act = MA_2CLK; break;
      case GDK_3BUTTON_PRESS: act = MA_3CLK; break;
      default: return FALSE;           /* don't know this event type */
    }

    if (send_raw_mouse && !(inst->cfg.mouse_override && shift) &&
        act != MA_CLICK && act != MA_RELEASE)
        return TRUE;                   /* we ignore these in raw mouse mode */

    x = (event->x - inst->cfg.window_border) / inst->font_width;
    y = (event->y - inst->cfg.window_border) / inst->font_height;

    term_mouse(inst->term, button, translate_button(button), act,
               x, y, shift, ctrl, alt);

    return TRUE;
}

gint motion_event(GtkWidget *widget, GdkEventMotion *event, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    int shift, ctrl, alt, x, y, button;

    /* Remember the timestamp. */
    inst->input_event_time = event->time;

    show_mouseptr(inst, 1);

    shift = event->state & GDK_SHIFT_MASK;
    ctrl = event->state & GDK_CONTROL_MASK;
    alt = event->state & GDK_MOD1_MASK;
    if (event->state & GDK_BUTTON1_MASK)
        button = MBT_LEFT;
    else if (event->state & GDK_BUTTON2_MASK)
        button = MBT_MIDDLE;
    else if (event->state & GDK_BUTTON3_MASK)
        button = MBT_RIGHT;
    else
        return FALSE;                  /* don't even know what button! */

    x = (event->x - inst->cfg.window_border) / inst->font_width;
    y = (event->y - inst->cfg.window_border) / inst->font_height;

    term_mouse(inst->term, button, translate_button(button), MA_DRAG,
               x, y, shift, ctrl, alt);

    return TRUE;
}

void frontend_keypress(void *handle)
{
    struct gui_data *inst = (struct gui_data *)handle;

    /*
     * If our child process has exited but not closed, terminate on
     * any keypress.
     */
    if (inst->exited)
        exit(0);
}

gint timer_func(gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    int exitcode;

    if (!inst->exited &&
        (exitcode = inst->back->exitcode(inst->backhandle)) >= 0) {
        inst->exited = TRUE;
        if (inst->cfg.close_on_exit == FORCE_ON ||
            (inst->cfg.close_on_exit == AUTO && exitcode == 0))
            exit(0);                   /* just go. */
        if (inst->ldisc) {
            ldisc_free(inst->ldisc);
            inst->ldisc = NULL;
        }
        if (inst->back) {
            inst->back->free(inst->backhandle);
            inst->backhandle = NULL;
            inst->back = NULL;
            update_specials_menu(inst);
        }
        gtk_widget_show(inst->restartitem);
    }

    term_update(inst->term);
    term_blink(inst->term, 0);
    return TRUE;
}

void fd_input_func(gpointer data, gint sourcefd, GdkInputCondition condition)
{
    /*
     * We must process exceptional notifications before ordinary
     * readability ones, or we may go straight past the urgent
     * marker.
     */
    if (condition & GDK_INPUT_EXCEPTION)
        select_result(sourcefd, 4);
    if (condition & GDK_INPUT_READ)
        select_result(sourcefd, 1);
    if (condition & GDK_INPUT_WRITE)
        select_result(sourcefd, 2);
}

void destroy(GtkWidget *widget, gpointer data)
{
    gtk_main_quit();
}

gint focus_event(GtkWidget *widget, GdkEventFocus *event, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    inst->term->has_focus = event->in;
    term_out(inst->term);
    term_update(inst->term);
    show_mouseptr(inst, 1);
    return FALSE;
}

/*
 * set or clear the "raw mouse message" mode
 */
void set_raw_mouse_mode(void *frontend, int activate)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    activate = activate && !inst->cfg.no_mouse_rep;
    send_raw_mouse = activate;
    if (send_raw_mouse)
        inst->currcursor = inst->rawcursor;
    else
        inst->currcursor = inst->textcursor;
    show_mouseptr(inst, inst->mouseptr_visible);
}

void request_resize(void *frontend, int w, int h)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    int large_x, large_y;
    int offset_x, offset_y;
    int area_x, area_y;
    GtkRequisition inner, outer;

    /*
     * This is a heinous hack dreamed up by the gnome-terminal
     * people to get around a limitation in gtk. The problem is
     * that in order to set the size correctly we really need to be
     * calling gtk_window_resize - but that needs to know the size
     * of the _whole window_, not the drawing area. So what we do
     * is to set an artificially huge size request on the drawing
     * area, recompute the resulting size request on the window,
     * and look at the difference between the two. That gives us
     * the x and y offsets we need to translate drawing area size
     * into window size for real, and then we call
     * gtk_window_resize.
     */

    /*
     * We start by retrieving the current size of the whole window.
     * Adding a bit to _that_ will give us a value we can use as a
     * bogus size request which guarantees to be bigger than the
     * current size of the drawing area.
     */
    get_window_pixels(inst, &large_x, &large_y);
    large_x += 32;
    large_y += 32;

#if GTK_CHECK_VERSION(2,0,0)
    gtk_widget_set_size_request(inst->area, large_x, large_y);
#else
    gtk_widget_set_usize(inst->area, large_x, large_y);
#endif
    gtk_widget_size_request(inst->area, &inner);
    gtk_widget_size_request(inst->window, &outer);

    offset_x = outer.width - inner.width;
    offset_y = outer.height - inner.height;

    area_x = inst->font_width * w + 2*inst->cfg.window_border;
    area_y = inst->font_height * h + 2*inst->cfg.window_border;

    /*
     * Now we must set the size request on the drawing area back to
     * something sensible before we commit the real resize. Best
     * way to do this, I think, is to set it to what the size is
     * really going to end up being.
     */
#if GTK_CHECK_VERSION(2,0,0)
    gtk_widget_set_size_request(inst->area, area_x, area_y);
#else
    gtk_widget_set_usize(inst->area, area_x, area_y);
    gtk_drawing_area_size(GTK_DRAWING_AREA(inst->area), area_x, area_y);
#endif

    gtk_container_dequeue_resize_handler(GTK_CONTAINER(inst->window));

#if GTK_CHECK_VERSION(2,0,0)
    gtk_window_resize(GTK_WINDOW(inst->window),
                      area_x + offset_x, area_y + offset_y);
#else
    gdk_window_resize(inst->window->window,
                      area_x + offset_x, area_y + offset_y);
#endif
}

static void real_palette_set(struct gui_data *inst, int n, int r, int g, int b)
{
    gboolean success[1];

    inst->cols[n].red = r * 0x0101;
    inst->cols[n].green = g * 0x0101;
    inst->cols[n].blue = b * 0x0101;

    gdk_colormap_free_colors(inst->colmap, inst->cols + n, 1);
    gdk_colormap_alloc_colors(inst->colmap, inst->cols + n, 1,
                              FALSE, FALSE, success);
    if (!success[0])
        g_error("%s: couldn't allocate colour %d (#%02x%02x%02x)\n", appname,
                n, r, g, b);
}

void set_window_background(struct gui_data *inst)
{
    if (inst->area && inst->area->window)
        gdk_window_set_background(inst->area->window, &inst->cols[18]);
    if (inst->window && inst->window->window)
        gdk_window_set_background(inst->window->window, &inst->cols[18]);
}

void palette_set(void *frontend, int n, int r, int g, int b)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    static const int first[21] = {
        0, 2, 4, 6, 8, 10, 12, 14,
        1, 3, 5, 7, 9, 11, 13, 15,
        16, 17, 18, 20, 22
    };
    real_palette_set(inst, first[n], r, g, b);
    if (first[n] >= 18)
        real_palette_set(inst, first[n] + 1, r, g, b);
    if (first[n] == 18)
        set_window_background(inst);
}

void palette_reset(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    /* This maps colour indices in inst->cfg to those used in inst->cols. */
    static const int ww[] = {
        6, 7, 8, 9, 10, 11, 12, 13,
        14, 15, 16, 17, 18, 19, 20, 21,
        0, 1, 2, 3, 4, 5
    };
    gboolean success[NCOLOURS];
    int i;

    assert(lenof(ww) == NCOLOURS);

    if (!inst->colmap) {
        inst->colmap = gdk_colormap_get_system();
    } else {
        gdk_colormap_free_colors(inst->colmap, inst->cols, NCOLOURS);
    }

    for (i = 0; i < NCOLOURS; i++) {
        inst->cols[i].red = inst->cfg.colours[ww[i]][0] * 0x0101;
        inst->cols[i].green = inst->cfg.colours[ww[i]][1] * 0x0101;
        inst->cols[i].blue = inst->cfg.colours[ww[i]][2] * 0x0101;
    }

    gdk_colormap_alloc_colors(inst->colmap, inst->cols, NCOLOURS,
                              FALSE, FALSE, success);
    for (i = 0; i < NCOLOURS; i++) {
        if (!success[i])
            g_error("%s: couldn't allocate colour %d (#%02x%02x%02x)\n",
                    appname, i, inst->cfg.colours[i][0],
                    inst->cfg.colours[i][1], inst->cfg.colours[i][2]);
    }

    set_window_background(inst);
}

/* Ensure that all the cut buffers exist - according to the ICCCM, we must
 * do this before we start using cut buffers.
 */
void init_cutbuffers()
{
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER0, XA_STRING, 8, PropModeAppend, "", 0);
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER1, XA_STRING, 8, PropModeAppend, "", 0);
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER2, XA_STRING, 8, PropModeAppend, "", 0);
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER3, XA_STRING, 8, PropModeAppend, "", 0);
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER4, XA_STRING, 8, PropModeAppend, "", 0);
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER5, XA_STRING, 8, PropModeAppend, "", 0);
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER6, XA_STRING, 8, PropModeAppend, "", 0);
    XChangeProperty(GDK_DISPLAY(), GDK_ROOT_WINDOW(),
                    XA_CUT_BUFFER7, XA_STRING, 8, PropModeAppend, "", 0);
}

/* Store the data in a cut-buffer. */
void store_cutbuffer(char * ptr, int len)
{
    /* ICCCM says we must rotate the buffers before storing to buffer 0. */
    XRotateBuffers(GDK_DISPLAY(), 1);
    XStoreBytes(GDK_DISPLAY(), ptr, len);
}

/* Retrieve data from a cut-buffer.
 * Returned data needs to be freed with XFree().
 */
char * retrieve_cutbuffer(int * nbytes)
{
    char * ptr;
    ptr = XFetchBytes(GDK_DISPLAY(), nbytes);
    if (*nbytes <= 0 && ptr != 0) {
        XFree(ptr);
        ptr = 0;
    }
    return ptr;
}

void write_clip(void *frontend, wchar_t * data, int len, int must_deselect)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    if (inst->pasteout_data)
        sfree(inst->pasteout_data);
    if (inst->pasteout_data_ctext)
        sfree(inst->pasteout_data_ctext);
    if (inst->pasteout_data_utf8)
        sfree(inst->pasteout_data_utf8);

    /*
     * Set up UTF-8 and compound text paste data. This only happens
     * if we aren't in direct-to-font mode using the D800 hack.
     */
    if (!inst->direct_to_font) {
        wchar_t *tmp = data;
        int tmplen = len;
        XTextProperty tp;
        char *list[1];

        inst->pasteout_data_utf8 = snewn(len*6, char);
        inst->pasteout_data_utf8_len = len*6;
        inst->pasteout_data_utf8_len =
            charset_from_unicode(&tmp, &tmplen, inst->pasteout_data_utf8,
                                 inst->pasteout_data_utf8_len,
                                 CS_UTF8, NULL, NULL, 0);
        if (inst->pasteout_data_utf8_len == 0) {
            sfree(inst->pasteout_data_utf8);
            inst->pasteout_data_utf8 = NULL;
        } else {
            inst->pasteout_data_utf8 =
                sresize(inst->pasteout_data_utf8,
                        inst->pasteout_data_utf8_len + 1, char);
            inst->pasteout_data_utf8[inst->pasteout_data_utf8_len] = '\0';
        }

        /*
         * Now let Xlib convert our UTF-8 data into compound text.
         */
        list[0] = inst->pasteout_data_utf8;
        if (Xutf8TextListToTextProperty(GDK_DISPLAY(), list, 1,
                                        XCompoundTextStyle, &tp) == 0) {
            inst->pasteout_data_ctext = snewn(tp.nitems+1, char);
            memcpy(inst->pasteout_data_ctext, tp.value, tp.nitems);
            inst->pasteout_data_ctext_len = tp.nitems;
            XFree(tp.value);
        } else {
            inst->pasteout_data_ctext = NULL;
            inst->pasteout_data_ctext_len = 0;
        }
    } else {
        inst->pasteout_data_utf8 = NULL;
        inst->pasteout_data_utf8_len = 0;
        inst->pasteout_data_ctext = NULL;
        inst->pasteout_data_ctext_len = 0;
    }

    inst->pasteout_data = snewn(len*6, char);
    inst->pasteout_data_len = len*6;
    inst->pasteout_data_len = wc_to_mb(inst->ucsdata.line_codepage, 0,
                                       data, len, inst->pasteout_data,
                                       inst->pasteout_data_len,
                                       NULL, NULL, NULL);
    if (inst->pasteout_data_len == 0) {
        sfree(inst->pasteout_data);
        inst->pasteout_data = NULL;
    } else {
        inst->pasteout_data =
            sresize(inst->pasteout_data, inst->pasteout_data_len, char);
    }

    store_cutbuffer(inst->pasteout_data, inst->pasteout_data_len);

    if (gtk_selection_owner_set(inst->area, GDK_SELECTION_PRIMARY,
                                inst->input_event_time)) {
        gtk_selection_add_target(inst->area, GDK_SELECTION_PRIMARY,
                                 GDK_SELECTION_TYPE_STRING, 1);
        if (inst->pasteout_data_ctext)
            gtk_selection_add_target(inst->area, GDK_SELECTION_PRIMARY,
                                     compound_text_atom, 1);
        if (inst->pasteout_data_utf8)
            gtk_selection_add_target(inst->area, GDK_SELECTION_PRIMARY,
                                     utf8_string_atom, 1);
    }

    if (must_deselect)
        term_deselect(inst->term);
}

void selection_get(GtkWidget *widget, GtkSelectionData *seldata,
                   guint info, guint time_stamp, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    if (seldata->target == utf8_string_atom)
        gtk_selection_data_set(seldata, seldata->target, 8,
                               inst->pasteout_data_utf8,
                               inst->pasteout_data_utf8_len);
    else if (seldata->target == compound_text_atom)
        gtk_selection_data_set(seldata, seldata->target, 8,
                               inst->pasteout_data_ctext,
                               inst->pasteout_data_ctext_len);
    else
        gtk_selection_data_set(seldata, seldata->target, 8,
                               inst->pasteout_data, inst->pasteout_data_len);
}

gint selection_clear(GtkWidget *widget, GdkEventSelection *seldata,
                     gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;

    term_deselect(inst->term);
    if (inst->pasteout_data)
        sfree(inst->pasteout_data);
    if (inst->pasteout_data_ctext)
        sfree(inst->pasteout_data_ctext);
    if (inst->pasteout_data_utf8)
        sfree(inst->pasteout_data_utf8);
    inst->pasteout_data = NULL;
    inst->pasteout_data_len = 0;
    inst->pasteout_data_ctext = NULL;
    inst->pasteout_data_ctext_len = 0;
    inst->pasteout_data_utf8 = NULL;
    inst->pasteout_data_utf8_len = 0;
    return TRUE;
}

void request_paste(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    /*
     * In Unix, pasting is asynchronous: all we can do at the
     * moment is to call gtk_selection_convert(), and when the data
     * comes back _then_ we can call term_do_paste().
     */

    if (!inst->direct_to_font) {
        /*
         * First we attempt to retrieve the selection as a UTF-8
         * string (which we will convert to the correct code page
         * before sending to the session, of course). If that
         * fails, selection_received() will be informed and will
         * fall back to an ordinary string.
         */
        gtk_selection_convert(inst->area, GDK_SELECTION_PRIMARY,
                              utf8_string_atom,
                              inst->input_event_time);
    } else {
        /*
         * If we're in direct-to-font mode, we disable UTF-8
         * pasting, and go straight to ordinary string data.
         */
        gtk_selection_convert(inst->area, GDK_SELECTION_PRIMARY,
                              GDK_SELECTION_TYPE_STRING,
                              inst->input_event_time);
    }
}

gint idle_paste_func(gpointer data);   /* forward ref */

void selection_received(GtkWidget *widget, GtkSelectionData *seldata,
                        guint time, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    XTextProperty tp;
    char **list;
    char *text;
    int length, count, ret;
    int free_list_required = 0;
    int free_required = 0;
    int charset;

    if (seldata->target == utf8_string_atom && seldata->length <= 0) {
        /*
         * Failed to get a UTF-8 selection string. Try compound
         * text next.
         */
        gtk_selection_convert(inst->area, GDK_SELECTION_PRIMARY,
                              compound_text_atom,
                              inst->input_event_time);
        return;
    }

    if (seldata->target == compound_text_atom && seldata->length <= 0) {
        /*
         * Failed to get UTF-8 or compound text. Try an ordinary
         * string.
         */
        gtk_selection_convert(inst->area, GDK_SELECTION_PRIMARY,
                              GDK_SELECTION_TYPE_STRING,
                              inst->input_event_time);
        return;
    }

    /*
     * If we have data, but it's not of a type we can deal with,
     * we have to ignore the data.
     */
    if (seldata->length > 0 &&
        seldata->type != GDK_SELECTION_TYPE_STRING &&
        seldata->type != compound_text_atom &&
        seldata->type != utf8_string_atom)
        return;

    /*
     * If we have no data, try looking in a cut buffer.
     */
    if (seldata->length <= 0) {
        text = retrieve_cutbuffer(&length);
        if (length == 0)
            return;
        /* Xterm is rumoured to expect Latin-1, though I havn't checked the
         * source, so use that as a de-facto standard. */
        charset = CS_ISO8859_1;
        free_required = 1;
    } else {
        /*
         * Convert COMPOUND_TEXT into UTF-8.
         */
        if (seldata->type == compound_text_atom) {
            tp.value = seldata->data;
            tp.encoding = (Atom) seldata->type;
            tp.format = seldata->format;
            tp.nitems = seldata->length;
            ret = Xutf8TextPropertyToTextList(GDK_DISPLAY(), &tp,
                                              &list, &count);
            if (ret != 0 || count != 1) {
                /*
                 * Compound text failed; fall back to STRING.
                 */
                gtk_selection_convert(inst->area, GDK_SELECTION_PRIMARY,
                                      GDK_SELECTION_TYPE_STRING,
                                      inst->input_event_time);
                return;
            }
            text = list[0];
            length = strlen(list[0]);
            charset = CS_UTF8;
            free_list_required = 1;
        } else {
            text = (char *)seldata->data;
            length = seldata->length;
            charset = (seldata->type == utf8_string_atom ?
                       CS_UTF8 : inst->ucsdata.line_codepage);
        }
    }

    if (inst->pastein_data)
        sfree(inst->pastein_data);

    inst->pastein_data = snewn(length, wchar_t);
    inst->pastein_data_len = length;
    inst->pastein_data_len =
        mb_to_wc(charset, 0, text, length,
                 inst->pastein_data, inst->pastein_data_len);

    term_do_paste(inst->term);

    if (term_paste_pending(inst->term))
        inst->term_paste_idle_id = gtk_idle_add(idle_paste_func, inst);

    if (free_list_required)
        XFreeStringList(list);
    if (free_required)
        XFree(text);
}

gint idle_paste_func(gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;

    if (term_paste_pending(inst->term))
        term_paste(inst->term);
    else
        gtk_idle_remove(inst->term_paste_idle_id);

    return TRUE;
}


void get_clip(void *frontend, wchar_t ** p, int *len)
{
    struct gui_data *inst = (struct gui_data *)frontend;

    if (p) {
        *p = inst->pastein_data;
        *len = inst->pastein_data_len;
    }
}

static void set_window_titles(struct gui_data *inst)
{
    /*
     * We must always call set_icon_name after calling set_title,
     * since set_title will write both names. Irritating, but such
     * is life.
     */
    gtk_window_set_title(GTK_WINDOW(inst->window), inst->wintitle);
    if (!inst->cfg.win_name_always)
        gdk_window_set_icon_name(inst->window->window, inst->icontitle);
}

void set_title(void *frontend, char *title)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    strncpy(inst->wintitle, title, lenof(inst->wintitle));
    inst->wintitle[lenof(inst->wintitle)-1] = '\0';
    set_window_titles(inst);
}

void set_icon(void *frontend, char *title)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    strncpy(inst->icontitle, title, lenof(inst->icontitle));
    inst->icontitle[lenof(inst->icontitle)-1] = '\0';
    set_window_titles(inst);
}

void set_sbar(void *frontend, int total, int start, int page)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    if (!inst->cfg.scrollbar)
        return;
    inst->sbar_adjust->lower = 0;
    inst->sbar_adjust->upper = total;
    inst->sbar_adjust->value = start;
    inst->sbar_adjust->page_size = page;
    inst->sbar_adjust->step_increment = 1;
    inst->sbar_adjust->page_increment = page/2;
    inst->ignore_sbar = TRUE;
    gtk_adjustment_changed(inst->sbar_adjust);
    inst->ignore_sbar = FALSE;
}

void scrollbar_moved(GtkAdjustment *adj, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;

    if (!inst->cfg.scrollbar)
        return;
    if (!inst->ignore_sbar)
        term_scroll(inst->term, 1, (int)adj->value);
}

void sys_cursor(void *frontend, int x, int y)
{
    /*
     * This is meaningless under X.
     */
}

/*
 * This is still called when mode==BELL_VISUAL, even though the
 * visual bell is handled entirely within terminal.c, because we
 * may want to perform additional actions on any kind of bell (for
 * example, taskbar flashing in Windows).
 */
void beep(void *frontend, int mode)
{
    if (mode != BELL_VISUAL)
        gdk_beep();
}

int char_width(Context ctx, int uc)
{
    /*
     * Under X, any fixed-width font really _is_ fixed-width.
     * Double-width characters will be dealt with using a separate
     * font. For the moment we can simply return 1.
     */
    return 1;
}

Context get_ctx(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    struct draw_ctx *dctx;

    if (!inst->area->window)
        return NULL;

    dctx = snew(struct draw_ctx);
    dctx->inst = inst;
    dctx->gc = gdk_gc_new(inst->area->window);
    return dctx;
}

void free_ctx(Context ctx)
{
    struct draw_ctx *dctx = (struct draw_ctx *)ctx;
    /* struct gui_data *inst = dctx->inst; */
    GdkGC *gc = dctx->gc;
    gdk_gc_unref(gc);
    sfree(dctx);
}

/*
 * Draw a line of text in the window, at given character
 * coordinates, in given attributes.
 *
 * We are allowed to fiddle with the contents of `text'.
 */
void do_text_internal(Context ctx, int x, int y, wchar_t *text, int len,
                      unsigned long attr, int lattr)
{
    struct draw_ctx *dctx = (struct draw_ctx *)ctx;
    struct gui_data *inst = dctx->inst;
    GdkGC *gc = dctx->gc;

    int nfg, nbg, t, fontid, shadow, rlen, widefactor;

    nfg = ((attr & ATTR_FGMASK) >> ATTR_FGSHIFT);
    nfg = 2 * (nfg & 0xF) + (nfg & 0x10 ? 1 : 0);
    nbg = ((attr & ATTR_BGMASK) >> ATTR_BGSHIFT);
    nbg = 2 * (nbg & 0xF) + (nbg & 0x10 ? 1 : 0);
    if (attr & ATTR_REVERSE) {
        t = nfg;
        nfg = nbg;
        nbg = t;
    }
    if (inst->cfg.bold_colour && (attr & ATTR_BOLD))
        nfg |= 1;
    if (inst->cfg.bold_colour && (attr & ATTR_BLINK))
        nbg |= 1;
    if (attr & TATTR_ACTCURS) {
        nfg = NCOLOURS-2;
        nbg = NCOLOURS-1;
    }

    fontid = shadow = 0;

    if (attr & ATTR_WIDE) {
        widefactor = 2;
        fontid |= 2;
    } else {
        widefactor = 1;
    }

    if ((attr & ATTR_BOLD) && !inst->cfg.bold_colour) {
        if (inst->fonts[fontid | 1])
            fontid |= 1;
        else
            shadow = 1;
    }

    if ((lattr & LATTR_MODE) != LATTR_NORM) {
        x *= 2;
        if (x >= inst->term->cols)
            return;
        if (x + len*2*widefactor > inst->term->cols)
            len = (inst->term->cols-x)/2/widefactor;/* trim to LH half */
        rlen = len * 2;
    } else
        rlen = len;

    {
        GdkRectangle r;

        r.x = x*inst->font_width+inst->cfg.window_border;
        r.y = y*inst->font_height+inst->cfg.window_border;
        r.width = rlen*widefactor*inst->font_width;
        r.height = inst->font_height;
        gdk_gc_set_clip_rectangle(gc, &r);
    }

    gdk_gc_set_foreground(gc, &inst->cols[nbg]);
    gdk_draw_rectangle(inst->pixmap, gc, 1,
                       x*inst->font_width+inst->cfg.window_border,
                       y*inst->font_height+inst->cfg.window_border,
                       rlen*widefactor*inst->font_width, inst->font_height);

    gdk_gc_set_foreground(gc, &inst->cols[nfg]);
    {
        GdkWChar *gwcs;
        gchar *gcs;
        wchar_t *wcs;
        int i;

        wcs = snewn(len+1, wchar_t);
        for (i = 0; i < len; i++) {
            wcs[i] = text[i];
        }

        if (inst->fonts[fontid] == NULL) {
            /*
             * The font for this contingency does not exist.
             * Typically this means we've been given ATTR_WIDE
             * character and have no wide font. So we display
             * nothing at all; such is life.
             */
        } else if (inst->fontinfo[fontid].is_wide) {
            /*
             * At least one version of gdk_draw_text_wc() has a
             * weird bug whereby it reads `len' elements of the
             * input string, but only draws `len/2'. Hence I'm
             * going to make its input array twice as long as it
             * theoretically needs to be, and pass in twice the
             * actual number of characters. If a fixed gdk actually
             * takes the doubled length seriously, then (a) the
             * array will stand scrutiny up to the full length, (b)
             * the spare elements of the array are full of zeroes
             * which will probably be an empty glyph in the font,
             * and (c) the clip rectangle should prevent it causing
             * trouble anyway.
             */
            gwcs = snewn(len*2+1, GdkWChar);
            memset(gwcs, 0, sizeof(GdkWChar) * (len*2+1));
            /*
             * FIXME: when we have a wide-char equivalent of
             * from_unicode, use it instead of this.
             */
            for (i = 0; i <= len; i++)
                gwcs[i] = wcs[i];
            gdk_draw_text_wc(inst->pixmap, inst->fonts[fontid], gc,
                             x*inst->font_width+inst->cfg.window_border,
                             y*inst->font_height+inst->cfg.window_border+inst->fonts[0]->ascent,
                             gwcs, len*2);
            if (shadow)
                gdk_draw_text_wc(inst->pixmap, inst->fonts[fontid], gc,
                                 x*inst->font_width+inst->cfg.window_border+inst->cfg.shadowboldoffset,
                                 y*inst->font_height+inst->cfg.window_border+inst->fonts[0]->ascent,
                                 gwcs, len*2);
            sfree(gwcs);
        } else {
            gcs = snewn(len+1, gchar);
            wc_to_mb(inst->fontinfo[fontid].charset, 0,
                     wcs, len, gcs, len, ".", NULL, NULL);
            gdk_draw_text(inst->pixmap, inst->fonts[fontid], gc,
                          x*inst->font_width+inst->cfg.window_border,
                          y*inst->font_height+inst->cfg.window_border+inst->fonts[0]->ascent,
                          gcs, len);
            if (shadow)
                gdk_draw_text(inst->pixmap, inst->fonts[fontid], gc,
                              x*inst->font_width+inst->cfg.window_border+inst->cfg.shadowboldoffset,
                              y*inst->font_height+inst->cfg.window_border+inst->fonts[0]->ascent,
                              gcs, len);
            sfree(gcs);
        }
        sfree(wcs);
    }

    if (attr & ATTR_UNDER) {
        int uheight = inst->fonts[0]->ascent + 1;
        if (uheight >= inst->font_height)
            uheight = inst->font_height - 1;
        gdk_draw_line(inst->pixmap, gc, x*inst->font_width+inst->cfg.window_border,
                      y*inst->font_height + uheight + inst->cfg.window_border,
                      (x+len)*widefactor*inst->font_width-1+inst->cfg.window_border,
                      y*inst->font_height + uheight + inst->cfg.window_border);
    }

    if ((lattr & LATTR_MODE) != LATTR_NORM) {
        /*
         * I can't find any plausible StretchBlt equivalent in the
         * X server, so I'm going to do this the slow and painful
         * way. This will involve repeated calls to
         * gdk_draw_pixmap() to stretch the text horizontally. It's
         * O(N^2) in time and O(N) in network bandwidth, but you
         * try thinking of a better way. :-(
         */
        int i;
        for (i = 0; i < len * widefactor * inst->font_width; i++) {
            gdk_draw_pixmap(inst->pixmap, gc, inst->pixmap,
                            x*inst->font_width+inst->cfg.window_border + 2*i,
                            y*inst->font_height+inst->cfg.window_border,
                            x*inst->font_width+inst->cfg.window_border + 2*i+1,
                            y*inst->font_height+inst->cfg.window_border,
                            len * inst->font_width - i, inst->font_height);
        }
        len *= 2;
        if ((lattr & LATTR_MODE) != LATTR_WIDE) {
            int dt, db;
            /* Now stretch vertically, in the same way. */
            if ((lattr & LATTR_MODE) == LATTR_BOT)
                dt = 0, db = 1;
            else
                dt = 1, db = 0;
            for (i = 0; i < inst->font_height; i+=2) {
                gdk_draw_pixmap(inst->pixmap, gc, inst->pixmap,
                                x*inst->font_width+inst->cfg.window_border,
                                y*inst->font_height+inst->cfg.window_border+dt*i+db,
                                x*widefactor*inst->font_width+inst->cfg.window_border,
                                y*inst->font_height+inst->cfg.window_border+dt*(i+1),
                                len * inst->font_width, inst->font_height-i-1);
            }
        }
    }
}

void do_text(Context ctx, int x, int y, wchar_t *text, int len,
             unsigned long attr, int lattr)
{
    struct draw_ctx *dctx = (struct draw_ctx *)ctx;
    struct gui_data *inst = dctx->inst;
    GdkGC *gc = dctx->gc;
    int widefactor;

    do_text_internal(ctx, x, y, text, len, attr, lattr);

    if (attr & ATTR_WIDE) {
        widefactor = 2;
    } else {
        widefactor = 1;
    }

    if ((lattr & LATTR_MODE) != LATTR_NORM) {
        x *= 2;
        if (x >= inst->term->cols)
            return;
        if (x + len*2*widefactor > inst->term->cols)
            len = (inst->term->cols-x)/2/widefactor;/* trim to LH half */
        len *= 2;
    }

    gdk_draw_pixmap(inst->area->window, gc, inst->pixmap,
                    x*inst->font_width+inst->cfg.window_border,
                    y*inst->font_height+inst->cfg.window_border,
                    x*inst->font_width+inst->cfg.window_border,
                    y*inst->font_height+inst->cfg.window_border,
                    len*widefactor*inst->font_width, inst->font_height);
}

void do_cursor(Context ctx, int x, int y, wchar_t *text, int len,
               unsigned long attr, int lattr)
{
    struct draw_ctx *dctx = (struct draw_ctx *)ctx;
    struct gui_data *inst = dctx->inst;
    GdkGC *gc = dctx->gc;

    int active, passive, widefactor;

    if (attr & TATTR_PASCURS) {
        attr &= ~TATTR_PASCURS;
        passive = 1;
    } else
        passive = 0;
    if ((attr & TATTR_ACTCURS) && inst->cfg.cursor_type != 0) {
        attr &= ~TATTR_ACTCURS;
        active = 1;
    } else
        active = 0;
    do_text_internal(ctx, x, y, text, len, attr, lattr);

    if (attr & ATTR_WIDE) {
        widefactor = 2;
    } else {
        widefactor = 1;
    }

    if ((lattr & LATTR_MODE) != LATTR_NORM) {
        x *= 2;
        if (x >= inst->term->cols)
            return;
        if (x + len*2*widefactor > inst->term->cols)
            len = (inst->term->cols-x)/2/widefactor;/* trim to LH half */
        len *= 2;
    }

    if (inst->cfg.cursor_type == 0) {
        /*
         * An active block cursor will already have been done by
         * the above do_text call, so we only need to do anything
         * if it's passive.
         */
        if (passive) {
            gdk_gc_set_foreground(gc, &inst->cols[NCOLOURS-1]);
            gdk_draw_rectangle(inst->pixmap, gc, 0,
                               x*inst->font_width+inst->cfg.window_border,
                               y*inst->font_height+inst->cfg.window_border,
                               len*inst->font_width-1, inst->font_height-1);
        }
    } else {
        int uheight;
        int startx, starty, dx, dy, length, i;

        int char_width;

        if ((attr & ATTR_WIDE) || (lattr & LATTR_MODE) != LATTR_NORM)
            char_width = 2*inst->font_width;
        else
            char_width = inst->font_width;

        if (inst->cfg.cursor_type == 1) {
            uheight = inst->fonts[0]->ascent + 1;
            if (uheight >= inst->font_height)
                uheight = inst->font_height - 1;

            startx = x * inst->font_width + inst->cfg.window_border;
            starty = y * inst->font_height + inst->cfg.window_border + uheight;
            dx = 1;
            dy = 0;
            length = len * char_width;
        } else {
            int xadjust = 0;
            if (attr & TATTR_RIGHTCURS)
                xadjust = char_width - 1;
            startx = x * inst->font_width + inst->cfg.window_border + xadjust;
            starty = y * inst->font_height + inst->cfg.window_border;
            dx = 0;
            dy = 1;
            length = inst->font_height;
        }

        gdk_gc_set_foreground(gc, &inst->cols[NCOLOURS-1]);
        if (passive) {
            for (i = 0; i < length; i++) {
                if (i % 2 == 0) {
                    gdk_draw_point(inst->pixmap, gc, startx, starty);
                }
                startx += dx;
                starty += dy;
            }
        } else if (active) {
            gdk_draw_line(inst->pixmap, gc, startx, starty,
                          startx + (length-1) * dx, starty + (length-1) * dy);
        } /* else no cursor (e.g., blinked off) */
    }

    gdk_draw_pixmap(inst->area->window, gc, inst->pixmap,
                    x*inst->font_width+inst->cfg.window_border,
                    y*inst->font_height+inst->cfg.window_border,
                    x*inst->font_width+inst->cfg.window_border,
                    y*inst->font_height+inst->cfg.window_border,
                    len*widefactor*inst->font_width, inst->font_height);
}

GdkCursor *make_mouse_ptr(struct gui_data *inst, int cursor_val)
{
    /*
     * Truly hideous hack: GTK doesn't allow us to set the mouse
     * cursor foreground and background colours unless we've _also_
     * created our own cursor from bitmaps. Therefore, I need to
     * load the `cursor' font and draw glyphs from it on to
     * pixmaps, in order to construct my cursors with the fg and bg
     * I want. This is a gross hack, but it's more self-contained
     * than linking in Xlib to find the X window handle to
     * inst->area and calling XRecolorCursor, and it's more
     * futureproof than hard-coding the shapes as bitmap arrays.
     */
    static GdkFont *cursor_font = NULL;
    GdkPixmap *source, *mask;
    GdkGC *gc;
    GdkColor cfg = { 0, 65535, 65535, 65535 };
    GdkColor cbg = { 0, 0, 0, 0 };
    GdkColor dfg = { 1, 65535, 65535, 65535 };
    GdkColor dbg = { 0, 0, 0, 0 };
    GdkCursor *ret;
    gchar text[2];
    gint lb, rb, wid, asc, desc, w, h, x, y;

    if (cursor_val == -2) {
        gdk_font_unref(cursor_font);
        return NULL;
    }

    if (cursor_val >= 0 && !cursor_font)
        cursor_font = gdk_font_load("cursor");

    /*
     * Get the text extent of the cursor in question. We use the
     * mask character for this, because it's typically slightly
     * bigger than the main character.
     */
    if (cursor_val >= 0) {
        text[1] = '\0';
        text[0] = (char)cursor_val + 1;
        gdk_string_extents(cursor_font, text, &lb, &rb, &wid, &asc, &desc);
        w = rb-lb; h = asc+desc; x = -lb; y = asc;
    } else {
        w = h = 1;
        x = y = 0;
    }

    source = gdk_pixmap_new(NULL, w, h, 1);
    mask = gdk_pixmap_new(NULL, w, h, 1);

    /*
     * Draw the mask character on the mask pixmap.
     */
    gc = gdk_gc_new(mask);
    gdk_gc_set_foreground(gc, &dbg);
    gdk_draw_rectangle(mask, gc, 1, 0, 0, w, h);
    if (cursor_val >= 0) {
        text[1] = '\0';
        text[0] = (char)cursor_val + 1;
        gdk_gc_set_foreground(gc, &dfg);
        gdk_draw_text(mask, cursor_font, gc, x, y, text, 1);
    }
    gdk_gc_unref(gc);

    /*
     * Draw the main character on the source pixmap.
     */
    gc = gdk_gc_new(source);
    gdk_gc_set_foreground(gc, &dbg);
    gdk_draw_rectangle(source, gc, 1, 0, 0, w, h);
    if (cursor_val >= 0) {
        text[1] = '\0';
        text[0] = (char)cursor_val;
        gdk_gc_set_foreground(gc, &dfg);
        gdk_draw_text(source, cursor_font, gc, x, y, text, 1);
    }
    gdk_gc_unref(gc);

    /*
     * Create the cursor.
     */
    ret = gdk_cursor_new_from_pixmap(source, mask, &cfg, &cbg, x, y);

    /*
     * Clean up.
     */
    gdk_pixmap_unref(source);
    gdk_pixmap_unref(mask);

    return ret;
}

void modalfatalbox(char *p, ...)
{
    va_list ap;
    fprintf(stderr, "FATAL ERROR: ");
    va_start(ap, p);
    vfprintf(stderr, p, ap);
    va_end(ap);
    fputc('\n', stderr);
    exit(1);
}

void cmdline_error(char *p, ...)
{
    va_list ap;
    fprintf(stderr, "%s: ", appname);
    va_start(ap, p);
    vfprintf(stderr, p, ap);
    va_end(ap);
    fputc('\n', stderr);
    exit(1);
}

char *get_x_display(void *frontend)
{
    return gdk_get_display();
}

long get_windowid(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;
    return (long)GDK_WINDOW_XWINDOW(inst->area->window);
}

static void help(FILE *fp) {
    if(fprintf(fp,
"pterm option summary:\n"
"\n"
"  --display DISPLAY         Specify X display to use (note '--')\n"
"  -name PREFIX              Prefix when looking up resources (default: pterm)\n"
"  -fn FONT                  Normal text font\n"
"  -fb FONT                  Bold text font\n"
"  -geometry GEOMETRY        Position and size of window (size in characters)\n"
"  -sl LINES                 Number of lines of scrollback\n"
"  -fg COLOUR, -bg COLOUR    Foreground/background colour\n"
"  -bfg COLOUR, -bbg COLOUR  Foreground/background bold colour\n"
"  -cfg COLOUR, -bfg COLOUR  Foreground/background cursor colour\n"
"  -T TITLE                  Window title\n"
"  -ut, +ut                  Do(default) or do not update utmp\n"
"  -ls, +ls                  Do(default) or do not make shell a login shell\n"
"  -sb, +sb                  Do(default) or do not display a scrollbar\n"
"  -log PATH                 Log all output to a file\n"
"  -nethack                  Map numeric keypad to hjklyubn direction keys\n"
"  -xrm RESOURCE-STRING      Set an X resource\n"
"  -e COMMAND [ARGS...]      Execute command (consumes all remaining args)\n"
         ) < 0 || fflush(fp) < 0) {
        perror("output error");
        exit(1);
    }
}

int do_cmdline(int argc, char **argv, int do_everything,
               struct gui_data *inst, Config *cfg)
{
    int err = 0;
    char *val;

    /*
     * Macros to make argument handling easier. Note that because
     * they need to call `continue', they cannot be contained in
     * the usual do {...} while (0) wrapper to make them
     * syntactically single statements; hence it is not legal to
     * use one of these macros as an unbraced statement between
     * `if' and `else'.
     */
#define EXPECTS_ARG { \
    if (--argc <= 0) { \
        err = 1; \
        fprintf(stderr, "%s: %s expects an argument\n", appname, p); \
        continue; \
    } else \
        val = *++argv; \
}
#define SECOND_PASS_ONLY { if (!do_everything) continue; }

    while (--argc > 0) {
        char *p = *++argv;
        int ret;

        /*
         * Shameless cheating. Debian requires all X terminal
         * emulators to support `-T title'; but
         * cmdline_process_param will eat -T (it means no-pty) and
         * complain that pterm doesn't support it. So, in pterm
         * only, we convert -T into -title.
         */
        if ((cmdline_tooltype & TOOLTYPE_NONNETWORK) &&
            !strcmp(p, "-T"))
            p = "-title";

        ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
                                    do_everything ? 1 : -1, cfg);

        if (ret == -2) {
            cmdline_error("option \"%s\" requires an argument", p);
        } else if (ret == 2) {
            --argc, ++argv;            /* skip next argument */
            continue;
        } else if (ret == 1) {
            continue;
        }

        if (!strcmp(p, "-fn") || !strcmp(p, "-font")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            strncpy(cfg->font.name, val, sizeof(cfg->font.name));
            cfg->font.name[sizeof(cfg->font.name)-1] = '\0';

        } else if (!strcmp(p, "-fb")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            strncpy(cfg->boldfont.name, val, sizeof(cfg->boldfont.name));
            cfg->boldfont.name[sizeof(cfg->boldfont.name)-1] = '\0';

        } else if (!strcmp(p, "-fw")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            strncpy(cfg->widefont.name, val, sizeof(cfg->widefont.name));
            cfg->widefont.name[sizeof(cfg->widefont.name)-1] = '\0';

        } else if (!strcmp(p, "-fwb")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            strncpy(cfg->wideboldfont.name, val, sizeof(cfg->wideboldfont.name));
            cfg->wideboldfont.name[sizeof(cfg->wideboldfont.name)-1] = '\0';

        } else if (!strcmp(p, "-cs")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            strncpy(cfg->line_codepage, val, sizeof(cfg->line_codepage));
            cfg->line_codepage[sizeof(cfg->line_codepage)-1] = '\0';

        } else if (!strcmp(p, "-geometry")) {
            int flags, x, y, w, h;
            EXPECTS_ARG;
            SECOND_PASS_ONLY;

            flags = XParseGeometry(val, &x, &y, &w, &h);
            if (flags & WidthValue)
                cfg->width = w;
            if (flags & HeightValue)
                cfg->height = h;

            if (flags & (XValue | YValue)) {
                inst->xpos = x;
                inst->ypos = y;
                inst->gotpos = TRUE;
                inst->gravity = ((flags & XNegative ? 1 : 0) |
                                 (flags & YNegative ? 2 : 0));
            }

        } else if (!strcmp(p, "-sl")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            cfg->savelines = atoi(val);

        } else if (!strcmp(p, "-fg") || !strcmp(p, "-bg") ||
                   !strcmp(p, "-bfg") || !strcmp(p, "-bbg") ||
                   !strcmp(p, "-cfg") || !strcmp(p, "-cbg")) {
            GdkColor col;

            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            if (!gdk_color_parse(val, &col)) {
                err = 1;
                fprintf(stderr, "%s: unable to parse colour \"%s\"\n",
                        appname, val);
            } else {
                int index;
                index = (!strcmp(p, "-fg") ? 0 :
                         !strcmp(p, "-bg") ? 2 :
                         !strcmp(p, "-bfg") ? 1 :
                         !strcmp(p, "-bbg") ? 3 :
                         !strcmp(p, "-cfg") ? 4 :
                         !strcmp(p, "-cbg") ? 5 : -1);
                assert(index != -1);
                cfg->colours[index][0] = col.red / 256;
                cfg->colours[index][1] = col.green / 256;
                cfg->colours[index][2] = col.blue / 256;
            }

        } else if (use_pty_argv && !strcmp(p, "-e")) {
            /* This option swallows all further arguments. */
            if (!do_everything)
                break;

            if (--argc > 0) {
                int i;
                pty_argv = snewn(argc+1, char *);
                ++argv;
                for (i = 0; i < argc; i++)
                    pty_argv[i] = argv[i];
                pty_argv[argc] = NULL;
                break;                 /* finished command-line processing */
            } else
                err = 1, fprintf(stderr, "%s: -e expects an argument\n",
                                 appname);

        } else if (!strcmp(p, "-title")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            strncpy(cfg->wintitle, val, sizeof(cfg->wintitle));
            cfg->wintitle[sizeof(cfg->wintitle)-1] = '\0';

        } else if (!strcmp(p, "-log")) {
            EXPECTS_ARG;
            SECOND_PASS_ONLY;
            strncpy(cfg->logfilename.path, val, sizeof(cfg->logfilename.path));
            cfg->logfilename.path[sizeof(cfg->logfilename.path)-1] = '\0';
            cfg->logtype = LGTYP_DEBUG;

        } else if (!strcmp(p, "-ut-") || !strcmp(p, "+ut")) {
            SECOND_PASS_ONLY;
            cfg->stamp_utmp = 0;

        } else if (!strcmp(p, "-ut")) {
            SECOND_PASS_ONLY;
            cfg->stamp_utmp = 1;

        } else if (!strcmp(p, "-ls-") || !strcmp(p, "+ls")) {
            SECOND_PASS_ONLY;
            cfg->login_shell = 0;

        } else if (!strcmp(p, "-ls")) {
            SECOND_PASS_ONLY;
            cfg->login_shell = 1;

        } else if (!strcmp(p, "-nethack")) {
            SECOND_PASS_ONLY;
            cfg->nethack_keypad = 1;

        } else if (!strcmp(p, "-sb-") || !strcmp(p, "+sb")) {
            SECOND_PASS_ONLY;
            cfg->scrollbar = 0;

        } else if (!strcmp(p, "-sb")) {
            SECOND_PASS_ONLY;
            cfg->scrollbar = 0;

        } else if (!strcmp(p, "-name")) {
            EXPECTS_ARG;
            app_name = val;

        } else if (!strcmp(p, "-xrm")) {
            EXPECTS_ARG;
            provide_xrm_string(val);

        } else if(!strcmp(p, "-help") || !strcmp(p, "--help")) {
            help(stdout);
            exit(0);
            
        } else if(p[0] != '-' && (!do_everything ||
                                  process_nonoption_arg(p, cfg))) {
            /* do nothing */

        } else {
            err = 1;
            fprintf(stderr, "%s: unrecognized option '%s'\n", appname, p);
        }
    }

    return err;
}

static void block_signal(int sig, int block_it) {
  sigset_t ss;

  sigemptyset(&ss);
  sigaddset(&ss, sig);
  if(sigprocmask(block_it ? SIG_BLOCK : SIG_UNBLOCK, &ss, 0) < 0) {
    perror("sigprocmask");
    exit(1);
  }
}

/*
 * This function retrieves the character set encoding of a font. It
 * returns the character set without the X11 hack (in case the user
 * asks to use the font's own encoding).
 */
static int set_font_info(struct gui_data *inst, int fontid)
{
    GdkFont *font = inst->fonts[fontid];
    XFontStruct *xfs = GDK_FONT_XFONT(font);
    Display *disp = GDK_FONT_XDISPLAY(font);
    Atom charset_registry, charset_encoding;
    unsigned long registry_ret, encoding_ret;
    int retval = CS_NONE;

    charset_registry = XInternAtom(disp, "CHARSET_REGISTRY", False);
    charset_encoding = XInternAtom(disp, "CHARSET_ENCODING", False);
    inst->fontinfo[fontid].charset = CS_NONE;
    inst->fontinfo[fontid].is_wide = 0;
    if (XGetFontProperty(xfs, charset_registry, &registry_ret) &&
        XGetFontProperty(xfs, charset_encoding, &encoding_ret)) {
        char *reg, *enc;
        reg = XGetAtomName(disp, (Atom)registry_ret);
        enc = XGetAtomName(disp, (Atom)encoding_ret);
        if (reg && enc) {
            char *encoding = dupcat(reg, "-", enc, NULL);
            retval = inst->fontinfo[fontid].charset =
                charset_from_xenc(encoding);
            /* FIXME: when libcharset supports wide encodings fix this. */
            if (!strcasecmp(encoding, "iso10646-1")) {
                inst->fontinfo[fontid].is_wide = 1;
                retval = CS_UTF8;
            }

            /*
             * Hack for X line-drawing characters: if the primary
             * font is encoded as ISO-8859-anything, and has valid
             * glyphs in the first 32 char positions, it is assumed
             * that those glyphs are the VT100 line-drawing
             * character set.
             * 
             * Actually, we'll hack even harder by only checking
             * position 0x19 (vertical line, VT100 linedrawing
             * `x'). Then we can check it easily by seeing if the
             * ascent and descent differ.
             */
            if (inst->fontinfo[fontid].charset == CS_ISO8859_1) {
                int lb, rb, wid, asc, desc;
                gchar text[2];

                text[1] = '\0';
                text[0] = '\x12';
                gdk_string_extents(inst->fonts[fontid], text,
                                   &lb, &rb, &wid, &asc, &desc);
                if (asc != desc)
                    inst->fontinfo[fontid].charset = CS_ISO8859_1_X11;
            }

            sfree(encoding);
        }
    }

    return retval;
}

int uxsel_input_add(int fd, int rwx) {
    int flags = 0;
    if (rwx & 1) flags |= GDK_INPUT_READ;
    if (rwx & 2) flags |= GDK_INPUT_WRITE;
    if (rwx & 4) flags |= GDK_INPUT_EXCEPTION;
    return gdk_input_add(fd, flags, fd_input_func, NULL);
}

void uxsel_input_remove(int id) {
    gdk_input_remove(id);
}

char *guess_derived_font_name(GdkFont *font, int bold, int wide)
{
    XFontStruct *xfs = GDK_FONT_XFONT(font);
    Display *disp = GDK_FONT_XDISPLAY(font);
    Atom fontprop = XInternAtom(disp, "FONT", False);
    unsigned long ret;
    if (XGetFontProperty(xfs, fontprop, &ret)) {
        char *name = XGetAtomName(disp, (Atom)ret);
        if (name && name[0] == '-') {
            char *strings[13];
            char *dupname, *extrafree = NULL, *ret;
            char *p, *q;
            int nstr;

            p = q = dupname = dupstr(name); /* skip initial minus */
            nstr = 0;

            while (*p && nstr < lenof(strings)) {
                if (*p == '-') {
                    *p = '\0';
                    strings[nstr++] = p+1;
                }
                p++;
            }

            if (nstr < lenof(strings))
                return NULL;           /* XLFD was malformed */

            if (bold)
                strings[2] = "bold";

            if (wide) {
                /* 4 is `wideness', which obviously may have changed. */
                /* 5 is additional style, which may be e.g. `ja' or `ko'. */
                strings[4] = strings[5] = "*";
                strings[11] = extrafree = dupprintf("%d", 2*atoi(strings[11]));
            }

            ret = dupcat("-", strings[ 0], "-", strings[ 1], "-", strings[ 2],
                         "-", strings[ 3], "-", strings[ 4], "-", strings[ 5],
                         "-", strings[ 6], "-", strings[ 7], "-", strings[ 8],
                         "-", strings[ 9], "-", strings[10], "-", strings[11],
                         "-", strings[12], NULL);
            sfree(extrafree);
            sfree(dupname);

            return ret;
        }
    }
    return NULL;
}

void setup_fonts_ucs(struct gui_data *inst)
{
    int font_charset;
    char *name;
    int guessed;

    if (inst->fonts[0])
        gdk_font_unref(inst->fonts[0]);
    if (inst->fonts[1])
        gdk_font_unref(inst->fonts[1]);
    if (inst->fonts[2])
        gdk_font_unref(inst->fonts[2]);
    if (inst->fonts[3])
        gdk_font_unref(inst->fonts[3]);

    inst->fonts[0] = gdk_font_load(inst->cfg.font.name);
    if (!inst->fonts[0]) {
        fprintf(stderr, "%s: unable to load font \"%s\"\n", appname,
                inst->cfg.font.name);
        exit(1);
    }
    font_charset = set_font_info(inst, 0);

    if (inst->cfg.shadowbold) {
        inst->fonts[1] = NULL;
    } else {
        if (inst->cfg.boldfont.name[0]) {
            name = inst->cfg.boldfont.name;
            guessed = FALSE;
        } else {
            name = guess_derived_font_name(inst->fonts[0], TRUE, FALSE);
            guessed = TRUE;
        }
        inst->fonts[1] = name ? gdk_font_load(name) : NULL;
        if (inst->fonts[1]) {
            set_font_info(inst, 1);
        } else if (!guessed) {
            fprintf(stderr, "%s: unable to load bold font \"%s\"\n", appname,
                    inst->cfg.boldfont.name);
            exit(1);
        }
        if (guessed)
            sfree(name);
    }

    if (inst->cfg.widefont.name[0]) {
        name = inst->cfg.widefont.name;
        guessed = FALSE;
    } else {
        name = guess_derived_font_name(inst->fonts[0], FALSE, TRUE);
        guessed = TRUE;
    }
    inst->fonts[2] = name ? gdk_font_load(name) : NULL;
    if (inst->fonts[2]) {
        set_font_info(inst, 2);
    } else if (!guessed) {
        fprintf(stderr, "%s: unable to load wide font \"%s\"\n", appname,
                inst->cfg.widefont.name);
        exit(1);
    }
    if (guessed)
        sfree(name);

    if (inst->cfg.shadowbold) {
        inst->fonts[3] = NULL;
    } else {
        if (inst->cfg.wideboldfont.name[0]) {
            name = inst->cfg.wideboldfont.name;
            guessed = FALSE;
        } else {
            /*
             * Here we have some choices. We can widen the bold font,
             * bolden the wide font, or widen and bolden the standard
             * font. Try them all, in that order!
             */
            if (inst->cfg.widefont.name[0])
                name = guess_derived_font_name(inst->fonts[2], TRUE, FALSE);
            else if (inst->cfg.boldfont.name[0])
                name = guess_derived_font_name(inst->fonts[1], FALSE, TRUE);
            else
                name = guess_derived_font_name(inst->fonts[0], TRUE, TRUE);
            guessed = TRUE;
        }
        inst->fonts[3] = name ? gdk_font_load(name) : NULL;
        if (inst->fonts[3]) {
            set_font_info(inst, 3);
        } else if (!guessed) {
            fprintf(stderr, "%s: unable to load wide/bold font \"%s\"\n", appname,
                    inst->cfg.wideboldfont.name);
            exit(1);
        }
        if (guessed)
            sfree(name);
    }

    inst->font_width = gdk_char_width(inst->fonts[0], ' ');
    inst->font_height = inst->fonts[0]->ascent + inst->fonts[0]->descent;

    inst->direct_to_font = init_ucs(&inst->ucsdata,
                                    inst->cfg.line_codepage, font_charset,
                                    inst->cfg.vtmode);
}

void set_geom_hints(struct gui_data *inst)
{
    GdkGeometry geom;
    geom.min_width = inst->font_width + 2*inst->cfg.window_border;
    geom.min_height = inst->font_height + 2*inst->cfg.window_border;
    geom.max_width = geom.max_height = -1;
    geom.base_width = 2*inst->cfg.window_border;
    geom.base_height = 2*inst->cfg.window_border;
    geom.width_inc = inst->font_width;
    geom.height_inc = inst->font_height;
    geom.min_aspect = geom.max_aspect = 0;
    gtk_window_set_geometry_hints(GTK_WINDOW(inst->window), inst->area, &geom,
                                  GDK_HINT_MIN_SIZE | GDK_HINT_BASE_SIZE |
                                  GDK_HINT_RESIZE_INC);
}

void clear_scrollback_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    term_clrsb(inst->term);
}

void reset_terminal_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    term_pwron(inst->term);
    if (inst->ldisc)
        ldisc_send(inst->ldisc, NULL, 0, 0);
}

void copy_all_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    term_copyall(inst->term);
}

void special_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    int code = GPOINTER_TO_INT(gtk_object_get_data(GTK_OBJECT(item),
                                                   "user-data"));

    if (inst->back)
        inst->back->special(inst->backhandle, code);
}

void about_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    about_box(inst->window);
}

void event_log_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    showeventlog(inst->eventlogstuff, inst->window);
}

void change_settings_menuitem(GtkMenuItem *item, gpointer data)
{
    /* This maps colour indices in inst->cfg to those used in inst->cols. */
    static const int ww[] = {
        6, 7, 8, 9, 10, 11, 12, 13,
        14, 15, 16, 17, 18, 19, 20, 21,
        0, 1, 2, 3, 4, 5
    };
    struct gui_data *inst = (struct gui_data *)data;
    char *title = dupcat(appname, " Reconfiguration", NULL);
    Config cfg2, oldcfg;
    int i, need_size;

    cfg2 = inst->cfg;                  /* structure copy */

    if (do_config_box(title, &cfg2, 1)) {

        oldcfg = inst->cfg;            /* structure copy */
        inst->cfg = cfg2;              /* structure copy */

        /* Pass new config data to the logging module */
        log_reconfig(inst->logctx, &cfg2);
        /*
         * Flush the line discipline's edit buffer in the case
         * where local editing has just been disabled.
         */
        if (inst->ldisc)
            ldisc_send(inst->ldisc, NULL, 0, 0);
        /* Pass new config data to the terminal */
        term_reconfig(inst->term, &cfg2);
        /* Pass new config data to the back end */
        if (inst->back)
            inst->back->reconfig(inst->backhandle, &cfg2);

        /*
         * Just setting inst->cfg is sufficient to cause colour
         * setting changes to appear on the next ESC]R palette
         * reset. But we should also check whether any colour
         * settings have been changed, and revert the ones that
         * have to the new default, on the assumption that the user
         * is most likely to want an immediate update.
         */
        for (i = 0; i < NCOLOURS; i++) {
            if (oldcfg.colours[ww[i]][0] != cfg2.colours[ww[i]][0] ||
                oldcfg.colours[ww[i]][1] != cfg2.colours[ww[i]][1] ||
                oldcfg.colours[ww[i]][2] != cfg2.colours[ww[i]][2]) {
                real_palette_set(inst, i, cfg2.colours[ww[i]][0],
                                 cfg2.colours[ww[i]][1],
                                 cfg2.colours[ww[i]][2]);

                /*
                 * If the default background has changed, we must
                 * repaint the space in between the window border
                 * and the text area.
                 */
                if (i == 18) {
                    set_window_background(inst);
                    draw_backing_rect(inst);
                }
            }
        }

        /*
         * If the scrollbar needs to be shown, hidden, or moved
         * from one end to the other of the window, do so now.
         */
        if (oldcfg.scrollbar != cfg2.scrollbar) {
            if (cfg2.scrollbar)
                gtk_widget_show(inst->sbar);
            else
                gtk_widget_hide(inst->sbar);
        }
        if (oldcfg.scrollbar_on_left != cfg2.scrollbar_on_left) {
            gtk_box_reorder_child(inst->hbox, inst->sbar,
                                  cfg2.scrollbar_on_left ? 0 : 1);
        }

        /*
         * Change the window title, if required.
         */
        if (strcmp(oldcfg.wintitle, cfg2.wintitle))
            set_title(inst, cfg2.wintitle);
        set_window_titles(inst);

        /*
         * Redo the whole tangled fonts and Unicode mess if
         * necessary.
         */
        if (strcmp(oldcfg.font.name, cfg2.font.name) ||
            strcmp(oldcfg.boldfont.name, cfg2.boldfont.name) ||
            strcmp(oldcfg.widefont.name, cfg2.widefont.name) ||
            strcmp(oldcfg.wideboldfont.name, cfg2.wideboldfont.name) ||
            strcmp(oldcfg.line_codepage, cfg2.line_codepage) ||
            oldcfg.vtmode != cfg2.vtmode ||
            oldcfg.shadowbold != cfg2.shadowbold) {
            setup_fonts_ucs(inst);
            need_size = 1;
        } else
            need_size = 0;

        /*
         * Resize the window.
         */
        if (oldcfg.width != cfg2.width || oldcfg.height != cfg2.height ||
            oldcfg.window_border != cfg2.window_border || need_size) {
            set_geom_hints(inst);
            request_resize(inst, cfg2.width, cfg2.height);
        } else {
            /*
             * The above will have caused a call to term_size() for
             * us if it happened. If the user has fiddled with only
             * the scrollback size, the above will not have
             * happened and we will need an explicit term_size()
             * here.
             */
            if (oldcfg.savelines != cfg2.savelines)
                term_size(inst->term, inst->term->rows, inst->term->cols,
                          cfg2.savelines);
        }

        term_invalidate(inst->term);

        /*
         * We do an explicit full redraw here to ensure the window
         * border has been redrawn as well as the text area.
         */
        gtk_widget_queue_draw(inst->area);
    }
    sfree(title);
}

void fork_and_exec_self(struct gui_data *inst, int fd_to_close, ...)
{
    /*
     * Re-execing ourself is not an exact science under Unix. I do
     * the best I can by using /proc/self/exe if available and by
     * assuming argv[0] can be found on $PATH if not.
     * 
     * Note that we also have to reconstruct the elements of the
     * original argv which gtk swallowed, since the user wants the
     * new session to appear on the same X display as the old one.
     */
    char **args;
    va_list ap;
    int i, n;
    int pid;

    /*
     * Collect the arguments with which to re-exec ourself.
     */
    va_start(ap, fd_to_close);
    n = 2;                             /* progname and terminating NULL */
    n += inst->ngtkargs;
    while (va_arg(ap, char *) != NULL)
        n++;
    va_end(ap);

    args = snewn(n, char *);
    args[0] = inst->progname;
    args[n-1] = NULL;
    for (i = 0; i < inst->ngtkargs; i++)
        args[i+1] = inst->gtkargvstart[i];

    i++;
    va_start(ap, fd_to_close);
    while ((args[i++] = va_arg(ap, char *)) != NULL);
    va_end(ap);

    assert(i == n);

    /*
     * Do the double fork.
     */
    pid = fork();
    if (pid < 0) {
        perror("fork");
        return;
    }

    if (pid == 0) {
        int pid2 = fork();
        if (pid2 < 0) {
            perror("fork");
            _exit(1);
        } else if (pid2 > 0) {
            /*
             * First child has successfully forked second child. My
             * Work Here Is Done. Note the use of _exit rather than
             * exit: the latter appears to cause destroy messages
             * to be sent to the X server. I suspect gtk uses
             * atexit.
             */
            _exit(0);
        }

        /*
         * If we reach here, we are the second child, so we now
         * actually perform the exec.
         */
        if (fd_to_close >= 0)
            close(fd_to_close);

        execv("/proc/self/exe", args);
        execvp(inst->progname, args);
        perror("exec");
        _exit(127);

    } else {
        int status;
        waitpid(pid, &status, 0);
    }

}

void dup_session_menuitem(GtkMenuItem *item, gpointer gdata)
{
    struct gui_data *inst = (struct gui_data *)gdata;
    /*
     * For this feature we must marshal cfg and (possibly) pty_argv
     * into a byte stream, create a pipe, and send this byte stream
     * to the child through the pipe.
     */
    int i, ret, size;
    char *data;
    char option[80];
    int pipefd[2];

    if (pipe(pipefd) < 0) {
        perror("pipe");
        return;
    }

    size = sizeof(inst->cfg);
    if (use_pty_argv && pty_argv) {
        for (i = 0; pty_argv[i]; i++)
            size += strlen(pty_argv[i]) + 1;
    }

    data = snewn(size, char);
    memcpy(data, &inst->cfg, sizeof(inst->cfg));
    if (use_pty_argv && pty_argv) {
        int p = sizeof(inst->cfg);
        for (i = 0; pty_argv[i]; i++) {
            strcpy(data + p, pty_argv[i]);
            p += strlen(pty_argv[i]) + 1;
        }
        assert(p == size);
    }

    sprintf(option, "---[%d,%d]", pipefd[0], size);
    fcntl(pipefd[0], F_SETFD, 0);
    fork_and_exec_self(inst, pipefd[1], option, NULL);
    close(pipefd[0]);

    i = ret = 0;
    while (i < size && (ret = write(pipefd[1], data + i, size - i)) > 0)
        i += ret;
    if (ret < 0)
        perror("write to pipe");
    close(pipefd[1]);
    sfree(data);
}

int read_dupsession_data(struct gui_data *inst, Config *cfg, char *arg)
{
    int fd, i, ret, size;
    char *data;

    if (sscanf(arg, "---[%d,%d]", &fd, &size) != 2) {
        fprintf(stderr, "%s: malformed magic argument `%s'\n", appname, arg);
        exit(1);
    }

    data = snewn(size, char);
    i = ret = 0;
    while (i < size && (ret = read(fd, data + i, size - i)) > 0)
        i += ret;
    if (ret < 0) {
        perror("read from pipe");
        exit(1);
    } else if (i < size) {
        fprintf(stderr, "%s: unexpected EOF in Duplicate Session data\n",
                appname);
        exit(1);
    }

    memcpy(cfg, data, sizeof(Config));
    if (use_pty_argv && size > sizeof(Config)) {
        int n = 0;
        i = sizeof(Config);
        while (i < size) {
            while (i < size && data[i]) i++;
            if (i >= size) {
                fprintf(stderr, "%s: malformed Duplicate Session data\n",
                        appname);
                exit(1);
            }
            i++;
            n++;
        }
        pty_argv = snewn(n+1, char *);
        pty_argv[n] = NULL;
        n = 0;
        i = sizeof(Config);
        while (i < size) {
            char *p = data + i;
            while (i < size && data[i]) i++;
            assert(i < size);
            i++;
            pty_argv[n++] = dupstr(p);
        }
    }

    return 0;
}

void new_session_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;

    fork_and_exec_self(inst, -1, NULL);
}

void restart_session_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;

    if (!inst->back) {
        logevent(inst, "----- Session restarted -----");
        start_backend(inst);
        inst->exited = FALSE;
    }
}

void saved_session_menuitem(GtkMenuItem *item, gpointer data)
{
    struct gui_data *inst = (struct gui_data *)data;
    char *str = (char *)gtk_object_get_data(GTK_OBJECT(item), "user-data");

    fork_and_exec_self(inst, -1, "-load", str, NULL);
}

void saved_session_freedata(GtkMenuItem *item, gpointer data)
{
    char *str = (char *)gtk_object_get_data(GTK_OBJECT(item), "user-data");

    sfree(str);
}

void update_specials_menu(void *frontend)
{
    struct gui_data *inst = (struct gui_data *)frontend;

    const struct telnet_special *specials;

    if (inst->back)
        specials = inst->back->get_specials(inst->backhandle);
    else
        specials = NULL;

    gtk_container_foreach(GTK_CONTAINER(inst->specialsmenu),
                          (GtkCallback)gtk_widget_destroy, NULL);
    if (specials) {
        int i;
        GtkWidget *menuitem;
        for (i = 0; specials[i].name; i++) {
            if (*specials[i].name) {
                menuitem = gtk_menu_item_new_with_label(specials[i].name);
                gtk_object_set_data(GTK_OBJECT(menuitem), "user-data",
                                    GINT_TO_POINTER(specials[i].code));
                gtk_signal_connect(GTK_OBJECT(menuitem), "activate",
                                   GTK_SIGNAL_FUNC(special_menuitem), inst);
            } else
                menuitem = gtk_menu_item_new();
            gtk_container_add(GTK_CONTAINER(inst->specialsmenu), menuitem);
            gtk_widget_show(menuitem);
        }
        gtk_widget_show(inst->specialsitem1);
        gtk_widget_show(inst->specialsitem2);
    } else {
        gtk_widget_hide(inst->specialsitem1);
        gtk_widget_hide(inst->specialsitem2);
    }
}

static void start_backend(struct gui_data *inst)
{
    extern Backend *select_backend(Config *cfg);
    char *realhost;
    const char *error;

    inst->back = select_backend(&inst->cfg);

    error = inst->back->init((void *)inst, &inst->backhandle,
                             &inst->cfg, inst->cfg.host, inst->cfg.port,
                             &realhost, inst->cfg.tcp_nodelay,
                             inst->cfg.tcp_keepalives);

    if (error) {
        char *msg = dupprintf("Unable to open connection to %s:\n%s",
                              inst->cfg.host, error);
        inst->exited = TRUE;
        fatal_message_box(inst->window, msg);
        sfree(msg);
        exit(0);
    }

    if (inst->cfg.wintitle[0]) {
        set_title(inst, inst->cfg.wintitle);
        set_icon(inst, inst->cfg.wintitle);
    } else {
        char *title = make_default_wintitle(realhost);
        set_title(inst, title);
        set_icon(inst, title);
        sfree(title);
    }
    inst->back->provide_logctx(inst->backhandle, inst->logctx);
    update_specials_menu(inst);

    term_provide_resize_fn(inst->term, inst->back->size, inst->backhandle);

    inst->ldisc =
        ldisc_create(&inst->cfg, inst->term, inst->back, inst->backhandle,
                     inst);

    gtk_widget_hide(inst->restartitem);
}

int pt_main(int argc, char **argv)
{
    extern int cfgbox(Config *cfg);
    struct gui_data *inst;

    /*
     * Create an instance structure and initialise to zeroes
     */
    inst = snew(struct gui_data);
    memset(inst, 0, sizeof(*inst));
    inst->alt_keycode = -1;            /* this one needs _not_ to be zero */

    /* defer any child exit handling until we're ready to deal with
     * it */
    block_signal(SIGCHLD, 1);

    inst->progname = argv[0];
    /*
     * Copy the original argv before letting gtk_init fiddle with
     * it. It will be required later.
     */
    {
        int i, oldargc;
        inst->gtkargvstart = snewn(argc-1, char *);
        for (i = 1; i < argc; i++)
            inst->gtkargvstart[i-1] = dupstr(argv[i]);
        oldargc = argc;
        gtk_init(&argc, &argv);
        inst->ngtkargs = oldargc - argc;
    }

    if (argc > 1 && !strncmp(argv[1], "---", 3)) {
        read_dupsession_data(inst, &inst->cfg, argv[1]);
        /* Splatter this argument so it doesn't clutter a ps listing */
        memset(argv[1], 0, strlen(argv[1]));
    } else {
        if (do_cmdline(argc, argv, 0, inst, &inst->cfg))
            exit(1);                   /* pre-defaults pass to get -class */
        do_defaults(NULL, &inst->cfg);
        if (do_cmdline(argc, argv, 1, inst, &inst->cfg))
            exit(1);                   /* post-defaults, do everything */

        cmdline_run_saved(&inst->cfg);

        if (!*inst->cfg.host && !cfgbox(&inst->cfg))
            exit(0);                   /* config box hit Cancel */
    }

    if (!compound_text_atom)
        compound_text_atom = gdk_atom_intern("COMPOUND_TEXT", FALSE);
    if (!utf8_string_atom)
        utf8_string_atom = gdk_atom_intern("UTF8_STRING", FALSE);

    setup_fonts_ucs(inst);
    init_cutbuffers();

    inst->window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

    /*
     * Set up the colour map.
     */
    palette_reset(inst);

    inst->width = inst->cfg.width;
    inst->height = inst->cfg.height;

    inst->area = gtk_drawing_area_new();
    gtk_drawing_area_size(GTK_DRAWING_AREA(inst->area),
                          inst->font_width * inst->cfg.width + 2*inst->cfg.window_border,
                          inst->font_height * inst->cfg.height + 2*inst->cfg.window_border);
    inst->sbar_adjust = GTK_ADJUSTMENT(gtk_adjustment_new(0,0,0,0,0,0));
    inst->sbar = gtk_vscrollbar_new(inst->sbar_adjust);
    inst->hbox = GTK_BOX(gtk_hbox_new(FALSE, 0));
    /*
     * We always create the scrollbar; it remains invisible if
     * unwanted, so we can pop it up quickly if it suddenly becomes
     * desirable.
     */
    if (inst->cfg.scrollbar_on_left)
        gtk_box_pack_start(inst->hbox, inst->sbar, FALSE, FALSE, 0);
    gtk_box_pack_start(inst->hbox, inst->area, TRUE, TRUE, 0);
    if (!inst->cfg.scrollbar_on_left)
        gtk_box_pack_start(inst->hbox, inst->sbar, FALSE, FALSE, 0);

    gtk_container_add(GTK_CONTAINER(inst->window), GTK_WIDGET(inst->hbox));

    set_geom_hints(inst);

    gtk_widget_show(inst->area);
    if (inst->cfg.scrollbar)
        gtk_widget_show(inst->sbar);
    else
        gtk_widget_hide(inst->sbar);
    gtk_widget_show(GTK_WIDGET(inst->hbox));

    if (inst->gotpos) {
        int x = inst->xpos, y = inst->ypos;
        GtkRequisition req;
        gtk_widget_size_request(GTK_WIDGET(inst->window), &req);
        if (inst->gravity & 1) x += gdk_screen_width() - req.width;
        if (inst->gravity & 2) y += gdk_screen_height() - req.height;
        gtk_window_set_position(GTK_WINDOW(inst->window), GTK_WIN_POS_NONE);
        gtk_widget_set_uposition(GTK_WIDGET(inst->window), x, y);
    }

    gtk_signal_connect(GTK_OBJECT(inst->window), "destroy",
                       GTK_SIGNAL_FUNC(destroy), inst);
    gtk_signal_connect(GTK_OBJECT(inst->window), "delete_event",
                       GTK_SIGNAL_FUNC(delete_window), inst);
    gtk_signal_connect(GTK_OBJECT(inst->window), "key_press_event",
                       GTK_SIGNAL_FUNC(key_event), inst);
    gtk_signal_connect(GTK_OBJECT(inst->window), "key_release_event",
                       GTK_SIGNAL_FUNC(key_event), inst);
    gtk_signal_connect(GTK_OBJECT(inst->window), "focus_in_event",
                       GTK_SIGNAL_FUNC(focus_event), inst);
    gtk_signal_connect(GTK_OBJECT(inst->window), "focus_out_event",
                       GTK_SIGNAL_FUNC(focus_event), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "configure_event",
                       GTK_SIGNAL_FUNC(configure_area), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "expose_event",
                       GTK_SIGNAL_FUNC(expose_area), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "button_press_event",
                       GTK_SIGNAL_FUNC(button_event), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "button_release_event",
                       GTK_SIGNAL_FUNC(button_event), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "motion_notify_event",
                       GTK_SIGNAL_FUNC(motion_event), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "selection_received",
                       GTK_SIGNAL_FUNC(selection_received), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "selection_get",
                       GTK_SIGNAL_FUNC(selection_get), inst);
    gtk_signal_connect(GTK_OBJECT(inst->area), "selection_clear_event",
                       GTK_SIGNAL_FUNC(selection_clear), inst);
    if (inst->cfg.scrollbar)
        gtk_signal_connect(GTK_OBJECT(inst->sbar_adjust), "value_changed",
                           GTK_SIGNAL_FUNC(scrollbar_moved), inst);
    gtk_timeout_add(20, timer_func, inst);
    gtk_widget_add_events(GTK_WIDGET(inst->area),
                          GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK |
                          GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
                          GDK_POINTER_MOTION_MASK | GDK_BUTTON_MOTION_MASK);

    gtk_widget_show(inst->window);

    set_window_background(inst);

    /*
     * Set up the Ctrl+rightclick context menu.
     */
    {
        GtkWidget *menuitem;
        char *s;
        extern const int use_event_log, new_session, saved_sessions;

        inst->menu = gtk_menu_new();

#define MKMENUITEM(title, func) do { \
    menuitem = title ? gtk_menu_item_new_with_label(title) : \
    gtk_menu_item_new(); \
    gtk_container_add(GTK_CONTAINER(inst->menu), menuitem); \
    gtk_widget_show(menuitem); \
    if (func != NULL) \
        gtk_signal_connect(GTK_OBJECT(menuitem), "activate", \
                               GTK_SIGNAL_FUNC(func), inst); \
} while (0)
        if (new_session)
            MKMENUITEM("New Session", new_session_menuitem);
        MKMENUITEM("Restart Session", restart_session_menuitem);
        inst->restartitem = menuitem;
        gtk_widget_hide(inst->restartitem);
        MKMENUITEM("Duplicate Session", dup_session_menuitem);
        if (saved_sessions) {
            struct sesslist sesslist;
            int i;

            inst->sessionsmenu = gtk_menu_new();

            get_sesslist(&sesslist, TRUE);
            for (i = 1; i < sesslist.nsessions; i++) {
                menuitem = gtk_menu_item_new_with_label(sesslist.sessions[i]);
                gtk_container_add(GTK_CONTAINER(inst->sessionsmenu), menuitem);
                gtk_widget_show(menuitem);
                gtk_object_set_data(GTK_OBJECT(menuitem), "user-data",
                                    dupstr(sesslist.sessions[i]));
                gtk_signal_connect(GTK_OBJECT(menuitem), "activate",
                                   GTK_SIGNAL_FUNC(saved_session_menuitem),
                                   inst);
                gtk_signal_connect(GTK_OBJECT(menuitem), "destroy",
                                   GTK_SIGNAL_FUNC(saved_session_freedata),
                                   inst);
            }
            get_sesslist(&sesslist, FALSE);

            MKMENUITEM("Saved Sessions", NULL);
            gtk_menu_item_set_submenu(GTK_MENU_ITEM(menuitem),
                                      inst->sessionsmenu);
        }
        MKMENUITEM(NULL, NULL);
        MKMENUITEM("Change Settings", change_settings_menuitem);
        MKMENUITEM(NULL, NULL);
        if (use_event_log)
            MKMENUITEM("Event Log", event_log_menuitem);
        MKMENUITEM("Special Commands", NULL);
        inst->specialsmenu = gtk_menu_new();
        gtk_menu_item_set_submenu(GTK_MENU_ITEM(menuitem), inst->specialsmenu);
        inst->specialsitem1 = menuitem;
        MKMENUITEM(NULL, NULL);
        inst->specialsitem2 = menuitem;
        MKMENUITEM("Clear Scrollback", clear_scrollback_menuitem);
        MKMENUITEM("Reset Terminal", reset_terminal_menuitem);
        MKMENUITEM("Copy All", copy_all_menuitem);
        MKMENUITEM(NULL, NULL);
        s = dupcat("About ", appname, NULL);
        MKMENUITEM(s, about_menuitem);
        sfree(s);
#undef MKMENUITEM
    }

    inst->textcursor = make_mouse_ptr(inst, GDK_XTERM);
    inst->rawcursor = make_mouse_ptr(inst, GDK_LEFT_PTR);
    inst->blankcursor = make_mouse_ptr(inst, -1);
    make_mouse_ptr(inst, -2);          /* clean up cursor font */
    inst->currcursor = inst->textcursor;
    show_mouseptr(inst, 1);

    inst->eventlogstuff = eventlogstuff_new();

    inst->term = term_init(&inst->cfg, &inst->ucsdata, inst);
    inst->logctx = log_init(inst, &inst->cfg);
    term_provide_logctx(inst->term, inst->logctx);

    uxsel_init();

    term_size(inst->term, inst->cfg.height, inst->cfg.width, inst->cfg.savelines);

    start_backend(inst);

    ldisc_send(inst->ldisc, NULL, 0, 0);/* cause ldisc to notice changes */

    /* now we're reday to deal with the child exit handler being
     * called */
    block_signal(SIGCHLD, 0);

    /*
     * Block SIGPIPE: if we attempt Duplicate Session or similar
     * and it falls over in some way, we certainly don't want
     * SIGPIPE terminating the main pterm/PuTTY. Note that we do
     * this _after_ (at least pterm) forks off its child process,
     * since the child wants SIGPIPE handled in the usual way.
     */
    block_signal(SIGPIPE, 1);

    inst->exited = FALSE;

    gtk_main();

    return 0;
}