At last! After much delay, much faffing back and forth, and much
[u/mdw/putty] / terminal.c
index 8736a29..3b14923 100644 (file)
@@ -56,6 +56,8 @@
 
 #define has_compat(x) ( ((CL_##x)&term->compatibility_level) != 0 )
 
+const char sco2ansicolour[] = { 0, 4, 2, 6, 1, 5, 3, 7 };
+
 #define sel_nl_sz  (sizeof(sel_nl)/sizeof(wchar_t))
 const wchar_t sel_nl[] = SEL_NL;
 
@@ -99,7 +101,7 @@ static unsigned long *resizeline(unsigned long *line, int cols)
         */
        oldlen = line[0];
        lineattrs = line[oldlen + 1];
-       line = srealloc(line, TSIZE * (2 + cols));
+       line = sresize(line, 2 + cols, TTYPE);
        line[0] = cols;
        for (i = oldlen; i < cols; i++)
            line[i + 1] = ERASE_CHAR;
@@ -110,6 +112,19 @@ static unsigned long *resizeline(unsigned long *line, int cols)
 }
 
 /*
+ * Get the number of lines in the scrollback.
+ */
+static int sblines(Terminal *term)
+{
+    int sblines = count234(term->scrollback);
+    if (term->cfg.erase_to_scrollback &&
+       term->alt_which && term->alt_screen) {
+           sblines += term->alt_sblines;
+    }
+    return sblines;
+}
+
+/*
  * Retrieve a line of the screen or of the scrollback, according to
  * whether the y coordinate is non-negative or negative
  * (respectively).
@@ -124,8 +139,19 @@ static unsigned long *lineptr(Terminal *term, int y, int lineno)
        whichtree = term->screen;
        treeindex = y;
     } else {
-       whichtree = term->scrollback;
-       treeindex = y + count234(term->scrollback);
+       int altlines = 0;
+       if (term->cfg.erase_to_scrollback &&
+           term->alt_which && term->alt_screen) {
+           altlines = term->alt_sblines;
+       }
+       if (y < -altlines) {
+           whichtree = term->scrollback;
+           treeindex = y + altlines + count234(term->scrollback);
+       } else {
+           whichtree = term->alt_screen;
+           treeindex = y + term->alt_sblines;
+           /* treeindex = y + count234(term->alt_screen); */
+       }
     }
     line = index234(whichtree, treeindex);
 
@@ -175,7 +201,7 @@ static void power_on(Terminal *term)
     term->in_vbell = FALSE;
     term->cursor_on = 1;
     term->big_cursor = 0;
-    term->save_attr = term->curr_attr = ATTR_DEFAULT;
+    term->default_attr = term->save_attr = term->curr_attr = ATTR_DEFAULT;
     term->term_editing = term->term_echoing = FALSE;
     term->app_cursor_keys = term->cfg.app_cursor;
     term->app_keypad_keys = term->cfg.app_keypad;
@@ -211,6 +237,15 @@ void term_update(Terminal *term)
            term->seen_disp_event = 0;
            need_sbar_update = TRUE;
        }
+
+       /* Allocate temporary buffers for Arabic shaping and bidi. */
+       if (!term->cfg.arabicshaping || !term->cfg.bidi)
+       {
+           term->wcFrom = sresize(term->wcFrom, term->cols, bidi_char);
+           term->ltemp = sresize(term->ltemp, term->cols+1, unsigned long);
+           term->wcTo = sresize(term->wcTo, term->cols, bidi_char);
+       }
+
        if (need_sbar_update)
            update_sbar(term);
        do_paint(term, ctx, TRUE);
@@ -297,8 +332,15 @@ void term_reconfig(Terminal *term, Config *cfg)
        term->alt_wrap = term->wrap = term->cfg.wrap_mode;
     if (reset_decom)
        term->alt_om = term->dec_om = term->cfg.dec_om;
-    if (reset_bce)
+    if (reset_bce) {
        term->use_bce = term->cfg.bce;
+       if (term->use_bce)
+           term->erase_char = (' ' | ATTR_ASCII |
+                               (term->curr_attr &
+                                (ATTR_FGMASK | ATTR_BGMASK)));
+       else
+           term->erase_char = ERASE_CHAR;
+    }
     if (reset_blink)
        term->blink_is_real = term->cfg.blinktext;
     if (reset_charclass)
@@ -331,6 +373,8 @@ void term_clrsb(Terminal *term)
     while ((line = delpos234(term->scrollback, 0)) != NULL) {
        sfree(line);
     }
+    term->tempsblines = 0;
+    term->alt_sblines = 0;
     update_sbar(term);
 }
 
@@ -346,7 +390,7 @@ Terminal *term_init(Config *mycfg, struct unicode_data *ucsdata,
      * Allocate a new Terminal structure and initialise the fields
      * that need it.
      */
-    term = smalloc(sizeof(Terminal));
+    term = snew(Terminal);
     term->frontend = frontend;
     term->ucsdata = ucsdata;
     term->cfg = *mycfg;                       /* STRUCTURE COPY */
@@ -374,6 +418,8 @@ Terminal *term_init(Config *mycfg, struct unicode_data *ucsdata,
     term->curstype = 0;
 
     term->screen = term->alt_screen = term->scrollback = NULL;
+    term->tempsblines = 0;
+    term->alt_sblines = 0;
     term->disptop = 0;
     term->disptext = term->dispcurs = NULL;
     term->tabs = NULL;
@@ -381,12 +427,22 @@ Terminal *term_init(Config *mycfg, struct unicode_data *ucsdata,
     term->rows = term->cols = -1;
     power_on(term);
     term->beephead = term->beeptail = NULL;
+#ifdef OPTIMISE_SCROLL
+    term->scrollhead = term->scrolltail = NULL;
+#endif /* OPTIMISE_SCROLL */
     term->nbeeps = 0;
     term->lastbeep = FALSE;
     term->beep_overloaded = FALSE;
     term->attr_mask = 0xffffffff;
     term->resize_fn = NULL;
     term->resize_ctx = NULL;
+    term->in_term_out = FALSE;
+    term->ltemp = NULL;
+    term->wcFrom = NULL;
+    term->wcTo = NULL;
+
+    term->bidi_cache_size = 0;
+    term->pre_bidi_cache = term->post_bidi_cache = NULL;
 
     return term;
 }
@@ -395,6 +451,7 @@ void term_free(Terminal *term)
 {
     unsigned long *line;
     struct beeptime *beep;
+    int i;
 
     while ((line = delpos234(term->scrollback, 0)) != NULL)
        sfree(line);
@@ -416,6 +473,17 @@ void term_free(Terminal *term)
        printer_finish_job(term->print_job);
     bufchain_clear(&term->printer_buf);
     sfree(term->paste_buffer);
+    sfree(term->ltemp);
+    sfree(term->wcFrom);
+    sfree(term->wcTo);
+
+    for (i = 0; i < term->bidi_cache_size; i++) {
+       sfree(term->pre_bidi_cache[i]);
+       sfree(term->post_bidi_cache[i]);
+    }
+    sfree(term->pre_bidi_cache);
+    sfree(term->post_bidi_cache);
+
     sfree(term);
 }
 
@@ -443,6 +511,7 @@ void term_size(Terminal *term, int newrows, int newcols, int newsavelines)
     if (term->rows == -1) {
        term->scrollback = newtree234(NULL);
        term->screen = newtree234(NULL);
+       term->tempsblines = 0;
        term->rows = 0;
     }
 
@@ -452,15 +521,14 @@ void term_size(Terminal *term, int newrows, int newcols, int newsavelines)
      * will take care of resizing each individual line if
      * necessary. So:
      * 
-     *  - If the new screen and the old screen differ in length, we
-     *    must shunt some lines in from the scrollback or out to
-     *    the scrollback.
-     * 
-     *  - If doing that fails to provide us with enough material to
-     *    fill the new screen (i.e. the number of rows needed in
-     *    the new screen exceeds the total number in the previous
-     *    screen+scrollback), we must invent some blank lines to
-     *    cover the gap.
+     *  - If the new screen is longer, we shunt lines in from temporary
+     *    scrollback if possible, otherwise we add new blank lines at
+     *    the bottom.
+     *
+     *  - If the new screen is shorter, we remove any blank lines at
+     *    the bottom if possible, otherwise shunt lines above the cursor
+     *    to scrollback if possible, otherwise delete lines below the
+     *    cursor.
      * 
      *  - Then, if the new scrollback length is less than the
      *    amount of scrollback we actually have, we must throw some
@@ -468,42 +536,69 @@ void term_size(Terminal *term, int newrows, int newcols, int newsavelines)
      */
     sblen = count234(term->scrollback);
     /* Do this loop to expand the screen if newrows > rows */
-    for (i = term->rows; i < newrows; i++) {
-       if (sblen > 0) {
+    assert(term->rows == count234(term->screen));
+    while (term->rows < newrows) {
+       if (term->tempsblines > 0) {
+           /* Insert a line from the scrollback at the top of the screen. */
+           assert(sblen >= term->tempsblines);
            line = delpos234(term->scrollback, --sblen);
+           term->tempsblines -= 1;
+           addpos234(term->screen, line, 0);
+           term->curs.y += 1;
+           term->savecurs.y += 1;
        } else {
-           line = smalloc(TSIZE * (newcols + 2));
+           /* Add a new blank line at the bottom of the screen. */
+           line = snewn(newcols + 2, TTYPE);
            line[0] = newcols;
            for (j = 0; j < newcols; j++)
                line[j + 1] = ERASE_CHAR;
-            line[newcols] = LATTR_NORM;
+            line[newcols + 1] = LATTR_NORM;
+           addpos234(term->screen, line, count234(term->screen));
        }
-       addpos234(term->screen, line, 0);
+       term->rows += 1;
     }
     /* Do this loop to shrink the screen if newrows < rows */
-    for (i = newrows; i < term->rows; i++) {
-       line = delpos234(term->screen, 0);
-       addpos234(term->scrollback, line, sblen++);
+    while (term->rows > newrows) {
+       if (term->curs.y < term->rows - 1) {
+           /* delete bottom row, unless it contains the cursor */
+           sfree(delpos234(term->screen, term->rows - 1));
+       } else {
+           /* push top row to scrollback */
+           line = delpos234(term->screen, 0);
+           addpos234(term->scrollback, line, sblen++);
+           term->tempsblines += 1;
+           term->curs.y -= 1;
+           term->savecurs.y -= 1;
+       }
+       term->rows -= 1;
     }
+    assert(term->rows == newrows);
     assert(count234(term->screen) == newrows);
+
+    /* Delete any excess lines from the scrollback. */
     while (sblen > newsavelines) {
        line = delpos234(term->scrollback, 0);
        sfree(line);
        sblen--;
     }
+    if (sblen < term->tempsblines)
+       term->tempsblines = sblen;
     assert(count234(term->scrollback) <= newsavelines);
+    assert(count234(term->scrollback) >= term->tempsblines);
     term->disptop = 0;
 
-    newdisp = smalloc(newrows * (newcols + 1) * TSIZE);
+    /* Make a new displayed text buffer. */
+    newdisp = snewn(newrows * (newcols + 1), TTYPE);
     for (i = 0; i < newrows * (newcols + 1); i++)
        newdisp[i] = ATTR_INVALID;
     sfree(term->disptext);
     term->disptext = newdisp;
     term->dispcurs = NULL;
 
+    /* Make a new alternate screen. */
     newalt = newtree234(NULL);
     for (i = 0; i < newrows; i++) {
-       line = smalloc(TSIZE * (newcols + 2));
+       line = snewn(newcols + 2, TTYPE);
        line[0] = newcols;
        for (j = 0; j < newcols; j++)
            line[j + 1] = term->erase_char;
@@ -516,16 +611,20 @@ void term_size(Terminal *term, int newrows, int newcols, int newsavelines)
        freetree234(term->alt_screen);
     }
     term->alt_screen = newalt;
+    term->alt_sblines = 0;
 
-    term->tabs = srealloc(term->tabs, newcols * sizeof(*term->tabs));
+    term->tabs = sresize(term->tabs, newcols, unsigned char);
     {
        int i;
        for (i = (term->cols > 0 ? term->cols : 0); i < newcols; i++)
            term->tabs[i] = (i % 8 == 0 ? TRUE : FALSE);
     }
 
-    if (term->rows > 0)
-       term->curs.y += newrows - term->rows;
+    /* Check that the cursor positions are still valid. */
+    if (term->savecurs.y < 0)
+       term->savecurs.y = 0;
+    if (term->savecurs.y >= newrows)
+       term->savecurs.y = newrows - 1;
     if (term->curs.y < 0)
        term->curs.y = 0;
     if (term->curs.y >= newrows)
@@ -562,6 +661,25 @@ void term_provide_resize_fn(Terminal *term,
        resize_fn(resize_ctx, term->cols, term->rows);
 }
 
+/* Find the bottom line on the screen that has any content.
+ * If only the top line has content, returns 0.
+ * If no lines have content, return -1.
+ */ 
+static int find_last_nonempty_line(Terminal * term, tree234 * screen)
+{
+    int i;
+    for (i = count234(screen) - 1; i >= 0; i--) {
+       unsigned long *line = index234(screen, i);
+       int j;
+       int cols = line[0];
+       for (j = 0; j < cols; j++) {
+           if (line[j + 1] != term->erase_char) break;
+       }
+       if (j != cols) break;
+    }
+    return i;
+}
+
 /*
  * Swap screens. If `reset' is TRUE and we have been asked to
  * switch to the alternate screen, we must bring most of its
@@ -583,6 +701,7 @@ static void swap_screen(Terminal *term, int which, int reset, int keep_cur_pos)
        ttr = term->alt_screen;
        term->alt_screen = term->screen;
        term->screen = ttr;
+       term->alt_sblines = find_last_nonempty_line(term, term->alt_screen) + 1;
        t = term->curs.x;
        if (!reset && !keep_cur_pos)
            term->curs.x = term->alt_x;
@@ -640,10 +759,7 @@ static void swap_screen(Terminal *term, int which, int reset, int keep_cur_pos)
  */
 static void update_sbar(Terminal *term)
 {
-    int nscroll;
-
-    nscroll = count234(term->scrollback);
-
+    int nscroll = sblines(term);
     set_sbar(term->frontend, nscroll + term->rows,
             nscroll + term->disptop, term->rows);
 }
@@ -690,14 +806,14 @@ static void scroll(Terminal *term, int topline, int botline, int lines, int sb)
            if (term->selstart.y >= topline && term->selstart.y <= botline) {
                term->selstart.y++;
                if (term->selstart.y > botline) {
-                   term->selstart.y = botline;
+                   term->selstart.y = botline + 1;
                    term->selstart.x = 0;
                }
            }
            if (term->selend.y >= topline && term->selend.y <= botline) {
                term->selend.y++;
                if (term->selend.y > botline) {
-                   term->selend.y = botline;
+                   term->selend.y = botline + 1;
                    term->selend.x = 0;
                }
            }
@@ -718,8 +834,9 @@ static void scroll(Terminal *term, int topline, int botline, int lines, int sb)
                if (sblen == term->savelines) {
                    sblen--, line2 = delpos234(term->scrollback, 0);
                } else {
-                   line2 = smalloc(TSIZE * (term->cols + 2));
+                   line2 = snewn(term->cols + 2, TTYPE);
                    line2[0] = term->cols;
+                   term->tempsblines += 1;
                }
                addpos234(term->scrollback, line, sblen);
                line = line2;
@@ -760,26 +877,29 @@ static void scroll(Terminal *term, int topline, int botline, int lines, int sb)
             */
            seltop = sb ? -term->savelines : topline;
 
-           if (term->selstart.y >= seltop &&
-               term->selstart.y <= botline) {
-               term->selstart.y--;
-               if (term->selstart.y < seltop) {
-                   term->selstart.y = seltop;
-                   term->selstart.x = 0;
+           if (term->selstate != NO_SELECTION) {
+               if (term->selstart.y >= seltop &&
+                   term->selstart.y <= botline) {
+                   term->selstart.y--;
+                   if (term->selstart.y < seltop) {
+                       term->selstart.y = seltop;
+                       term->selstart.x = 0;
+                   }
                }
-           }
-           if (term->selend.y >= seltop && term->selend.y <= botline) {
-               term->selend.y--;
-               if (term->selend.y < seltop) {
-                   term->selend.y = seltop;
-                   term->selend.x = 0;
+               if (term->selend.y >= seltop && term->selend.y <= botline) {
+                   term->selend.y--;
+                   if (term->selend.y < seltop) {
+                       term->selend.y = seltop;
+                       term->selend.x = 0;
+                   }
                }
-           }
-           if (term->selanchor.y >= seltop && term->selanchor.y <= botline) {
-               term->selanchor.y--;
-               if (term->selanchor.y < seltop) {
-                   term->selanchor.y = seltop;
-                   term->selanchor.x = 0;
+               if (term->selanchor.y >= seltop &&
+                   term->selanchor.y <= botline) {
+                   term->selanchor.y--;
+                   if (term->selanchor.y < seltop) {
+                       term->selanchor.y = seltop;
+                       term->selanchor.x = 0;
+                   }
                }
            }
 
@@ -795,6 +915,35 @@ static void scroll(Terminal *term, int topline, int botline, int lines, int sb)
 
 #ifdef OPTIMISE_SCROLL
 /*
+ * Add a scroll of a region on the screen into the pending scroll list.
+ * `lines' is +ve for scrolling forward, -ve for backward.
+ *
+ * If the scroll is on the same area as the last scroll in the list,
+ * merge them.
+ */
+static void save_scroll(Terminal *term, int topline, int botline, int lines)
+{
+    struct scrollregion *newscroll;
+    if (term->scrolltail &&
+       term->scrolltail->topline == topline && 
+       term->scrolltail->botline == botline) {
+       term->scrolltail->lines += lines;
+    } else {
+       newscroll = snew(struct scrollregion);
+       newscroll->topline = topline;
+       newscroll->botline = botline;
+       newscroll->lines = lines;
+       newscroll->next = NULL;
+
+       if (!term->scrollhead)
+           term->scrollhead = newscroll;
+       else
+           term->scrolltail->next = newscroll;
+       term->scrolltail = newscroll;
+    }
+}
+
+/*
  * Scroll the physical display, and our conception of it in disptext.
  */
 static void scroll_display(Terminal *term, int topline, int botline, int lines)
@@ -820,7 +969,7 @@ static void scroll_display(Terminal *term, int topline, int botline, int lines)
        for (i = 0; i < distance; i++)
            start[i] |= ATTR_INVALID;
     }
-    do_scroll(term->frontend, topline, botline, lines);
+    save_scroll(term, topline, botline, lines);
 }
 #endif /* OPTIMISE_SCROLL */
 
@@ -942,7 +1091,7 @@ static void erase_lots(Terminal *term,
 {
     pos start, end;
     int erase_lattr;
-    unsigned long *ldata;
+    int erasing_lines_from_top = 0;
 
     if (line_only) {
        start.y = term->curs.y;
@@ -972,19 +1121,44 @@ static void erase_lots(Terminal *term,
     if (start.y == 0 && start.x == 0 && end.y == term->rows)
        term_invalidate(term);
 
-    ldata = lineptr(start.y);
-    while (poslt(start, end)) {
-       if (start.x == term->cols) {
-            if (!erase_lattr)
-                ldata[start.x] &= ~(LATTR_WRAPPED | LATTR_WRAPPED2);
-            else
-                ldata[start.x] = LATTR_NORM;
-        } else {
-           ldata[start.x] = term->erase_char;
-        }
-       if (incpos(start) && start.y < term->rows)
-           ldata = lineptr(start.y);
+    /* Lines scrolled away shouldn't be brought back on if the terminal
+     * resizes. */
+    if (start.y == 0 && start.x == 0 && end.x == 0 && erase_lattr)
+       erasing_lines_from_top = 1;
+
+    if (term->cfg.erase_to_scrollback && erasing_lines_from_top) {
+       /* If it's a whole number of lines, starting at the top, and
+        * we're fully erasing them, erase by scrolling and keep the
+        * lines in the scrollback. */
+       int scrolllines = end.y;
+       if (end.y == term->rows) {
+           /* Shrink until we find a non-empty row.*/
+           scrolllines = find_last_nonempty_line(term, term->screen) + 1;
+       }
+       if (scrolllines > 0)
+           scroll(term, 0, scrolllines - 1, scrolllines, TRUE);
+       fix_cpos;
+    } else {
+       unsigned long *ldata = lineptr(start.y);
+       while (poslt(start, end)) {
+           if (start.x == term->cols) {
+               if (!erase_lattr)
+                   ldata[start.x] &= ~(LATTR_WRAPPED | LATTR_WRAPPED2);
+               else
+                   ldata[start.x] = LATTR_NORM;
+           } else {
+               ldata[start.x] = term->erase_char;
+           }
+           if (incpos(start) && start.y < term->rows)
+               ldata = lineptr(start.y);
+       }
     }
+
+    /* After an erase of lines from the top of the screen, we shouldn't
+     * bring the lines back again if the terminal enlarges (since the user or
+     * application has explictly thrown them away). */
+    if (erasing_lines_from_top && !(term->alt_which))
+       term->tempsblines = 0;
 }
 
 /*
@@ -1030,10 +1204,10 @@ static void toggle_mode(Terminal *term, int mode, int query, int state)
 
     if (query)
        switch (mode) {
-         case 1:                      /* application cursor keys */
+         case 1:                      /* DECCKM: application cursor keys */
            term->app_cursor_keys = state;
            break;
-         case 2:                      /* VT52 mode */
+         case 2:                      /* DECANM: VT52 mode */
            term->vt52_mode = !state;
            if (term->vt52_mode) {
                term->blink_is_real = FALSE;
@@ -1042,13 +1216,17 @@ static void toggle_mode(Terminal *term, int mode, int query, int state)
                term->blink_is_real = term->cfg.blinktext;
            }
            break;
-         case 3:                      /* 80/132 columns */
+         case 3:                      /* DECCOLM: 80/132 columns */
            deselect(term);
            if (!term->cfg.no_remote_resize)
                request_resize(term->frontend, state ? 132 : 80, term->rows);
            term->reset_132 = state;
+           term->alt_t = term->marg_t = 0;
+           term->alt_b = term->marg_b = term->rows - 1;
+           move(term, 0, 0, 0);
+           erase_lots(term, FALSE, TRUE, TRUE);
            break;
-         case 5:                      /* reverse video */
+         case 5:                      /* DECSCNM: reverse video */
            /*
             * Toggle reverse video. If we receive an OFF within the
             * visual bell timeout period after an ON, we trigger an
@@ -1077,21 +1255,21 @@ static void toggle_mode(Terminal *term, int mode, int query, int state)
            if (state)
                term_update(term);
            break;
-         case 6:                      /* DEC origin mode */
+         case 6:                      /* DECOM: DEC origin mode */
            term->dec_om = state;
            break;
-         case 7:                      /* auto wrap */
+         case 7:                      /* DECAWM: auto wrap */
            term->wrap = state;
            break;
-         case 8:                      /* auto key repeat */
+         case 8:                      /* DECARM: auto key repeat */
            term->repeat_off = !state;
            break;
-         case 10:                     /* set local edit mode */
+         case 10:                     /* DECEDM: set local edit mode */
            term->term_editing = state;
            if (term->ldisc)           /* cause ldisc to notice changes */
                ldisc_send(term->ldisc, NULL, 0, 0);
            break;
-         case 25:                     /* enable/disable cursor */
+         case 25:                     /* DECTCEM: enable/disable cursor */
            compatibility2(OTHER, VT220);
            term->cursor_on = state;
            term->seen_disp_event = TRUE;
@@ -1117,35 +1295,36 @@ static void toggle_mode(Terminal *term, int mode, int query, int state)
            term->disptop = 0;
            break;
          case 1048:                   /* save/restore cursor */
-           save_cursor(term, state);
+           if (!term->cfg.no_alt_screen)
+                save_cursor(term, state);
            if (!state) term->seen_disp_event = TRUE;
            break;
          case 1049:                   /* cursor & alternate screen */
-           if (state)
+           if (state && !term->cfg.no_alt_screen)
                save_cursor(term, state);
            if (!state) term->seen_disp_event = TRUE;
            compatibility(OTHER);
            deselect(term);
            swap_screen(term, term->cfg.no_alt_screen ? 0 : state, TRUE, FALSE);
-           if (!state)
+           if (!state && !term->cfg.no_alt_screen)
                save_cursor(term, state);
            term->disptop = 0;
            break;
     } else
        switch (mode) {
-         case 4:                      /* set insert mode */
+         case 4:                      /* IRM: set insert mode */
            compatibility(VT102);
            term->insert = state;
            break;
-         case 12:                     /* set echo mode */
+         case 12:                     /* SRM: set echo mode */
            term->term_echoing = !state;
            if (term->ldisc)           /* cause ldisc to notice changes */
                ldisc_send(term->ldisc, NULL, 0, 0);
            break;
-         case 20:                     /* Return sends ... */
+         case 20:                     /* LNM: Return sends ... */
            term->cr_lf_return = state;
            break;
-         case 34:                     /* Make cursor BIG */
+         case 34:                     /* WYULCURM: Make cursor BIG */
            compatibility2(OTHER, VT220);
            term->big_cursor = !state;
        }
@@ -1453,7 +1632,7 @@ void term_out(Terminal *term)
            /* Or normal C0 controls. */
        if ((c & -32) == 0 && term->termstate < DO_CTRLS) {
            switch (c) {
-             case '\005':             /* terminal type query */
+             case '\005':             /* ENQ: terminal type query */
                /* Strictly speaking this is VT100 but a VT100 defaults to
                 * no response. Other terminals respond at their option.
                 *
@@ -1485,7 +1664,7 @@ void term_out(Terminal *term)
                               abuf, d - abuf, 0);
                }
                break;
-             case '\007':
+             case '\007':            /* BEL: Bell */
                {
                    struct beeptime *newbeep;
                    unsigned long ticks;
@@ -1493,7 +1672,7 @@ void term_out(Terminal *term)
                    ticks = GETTICKCOUNT();
 
                    if (!term->beep_overloaded) {
-                       newbeep = smalloc(sizeof(struct beeptime));
+                       newbeep = snew(struct beeptime);
                        newbeep->ticks = ticks;
                        newbeep->next = NULL;
                        if (!term->beephead)
@@ -1548,10 +1727,10 @@ void term_out(Terminal *term)
                            term_update(term);
                        }
                    }
-                   term->disptop = 0;
+                   term->seen_disp_event = TRUE;
                }
                break;
-             case '\b':
+             case '\b':              /* BS: Back space */
                if (term->curs.x == 0 &&
                    (term->curs.y == 0 || term->wrap == 0))
                    /* do nothing */ ;
@@ -1564,15 +1743,15 @@ void term_out(Terminal *term)
                fix_cpos;
                term->seen_disp_event = TRUE;
                break;
-             case '\016':
+             case '\016':            /* LS1: Locking-shift one */
                compatibility(VT100);
                term->cset = 1;
                break;
-             case '\017':
+             case '\017':            /* LS0: Locking-shift zero */
                compatibility(VT100);
                term->cset = 0;
                break;
-             case '\033':
+             case '\033':            /* ESC: Escape */
                if (term->vt52_mode)
                    term->termstate = VT52_ESC;
                else {
@@ -1581,7 +1760,7 @@ void term_out(Terminal *term)
                    term->esc_query = FALSE;
                }
                break;
-             case '\015':
+             case '\015':            /* CR: Carriage return */
                term->curs.x = 0;
                term->wrapnext = FALSE;
                fix_cpos;
@@ -1590,7 +1769,7 @@ void term_out(Terminal *term)
                if (term->logctx)
                    logtraffic(term->logctx, (unsigned char) c, LGTYP_ASCII);
                break;
-             case '\014':
+             case '\014':            /* FF: Form feed */
                if (has_compat(SCOANSI)) {
                    move(term, 0, 0, 0);
                    erase_lots(term, FALSE, FALSE, TRUE);
@@ -1599,9 +1778,9 @@ void term_out(Terminal *term)
                    term->seen_disp_event = 1;
                    break;
                }
-             case '\013':
+             case '\013':            /* VT: Line tabulation */
                compatibility(VT100);
-             case '\012':
+             case '\012':            /* LF: Line feed */
                if (term->curs.y == term->marg_b)
                    scroll(term, term->marg_t, term->marg_b, 1, TRUE);
                else if (term->curs.y < term->rows - 1)
@@ -1615,7 +1794,7 @@ void term_out(Terminal *term)
                if (term->logctx)
                    logtraffic(term->logctx, (unsigned char) c, LGTYP_ASCII);
                break;
-             case '\t':
+             case '\t':              /* HT: Character tabulation */
                {
                    pos old_curs = term->curs;
                    unsigned long *ldata = lineptr(term->curs.y);
@@ -1761,36 +1940,36 @@ void term_out(Terminal *term)
                }
                term->termstate = TOPLEVEL;
                switch (ANSI(c, term->esc_query)) {
-                 case '[':            /* enter CSI mode */
+                 case '[':             /* enter CSI mode */
                    term->termstate = SEEN_CSI;
                    term->esc_nargs = 1;
                    term->esc_args[0] = ARG_DEFAULT;
                    term->esc_query = FALSE;
                    break;
-                 case ']':            /* xterm escape sequences */
+                 case ']':             /* OSC: xterm escape sequences */
                    /* Compatibility is nasty here, xterm, linux, decterm yuk! */
                    compatibility(OTHER);
                    term->termstate = SEEN_OSC;
                    term->esc_args[0] = 0;
                    break;
-                 case '7':            /* save cursor */
+                 case '7':             /* DECSC: save cursor */
                    compatibility(VT100);
                    save_cursor(term, TRUE);
                    break;
-                 case '8':            /* restore cursor */
+                 case '8':             /* DECRC: restore cursor */
                    compatibility(VT100);
                    save_cursor(term, FALSE);
                    term->seen_disp_event = TRUE;
                    break;
-                 case '=':
+                 case '=':             /* DECKPAM: Keypad application mode */
                    compatibility(VT100);
                    term->app_keypad_keys = TRUE;
                    break;
-                 case '>':
+                 case '>':             /* DECKPNM: Keypad numeric mode */
                    compatibility(VT100);
                    term->app_keypad_keys = FALSE;
                    break;
-                 case 'D':            /* exactly equivalent to LF */
+                 case 'D':            /* IND: exactly equivalent to LF */
                    compatibility(VT100);
                    if (term->curs.y == term->marg_b)
                        scroll(term, term->marg_t, term->marg_b, 1, TRUE);
@@ -1800,7 +1979,7 @@ void term_out(Terminal *term)
                    term->wrapnext = FALSE;
                    term->seen_disp_event = TRUE;
                    break;
-                 case 'E':            /* exactly equivalent to CR-LF */
+                 case 'E':            /* NEL: exactly equivalent to CR-LF */
                    compatibility(VT100);
                    term->curs.x = 0;
                    if (term->curs.y == term->marg_b)
@@ -1811,7 +1990,7 @@ void term_out(Terminal *term)
                    term->wrapnext = FALSE;
                    term->seen_disp_event = TRUE;
                    break;
-                 case 'M':            /* reverse index - backwards LF */
+                 case 'M':            /* RI: reverse index - backwards LF */
                    compatibility(VT100);
                    if (term->curs.y == term->marg_t)
                        scroll(term, term->marg_t, term->marg_b, -1, TRUE);
@@ -1821,13 +2000,13 @@ void term_out(Terminal *term)
                    term->wrapnext = FALSE;
                    term->seen_disp_event = TRUE;
                    break;
-                 case 'Z':            /* terminal type query */
+                 case 'Z':            /* DECID: terminal type query */
                    compatibility(VT100);
                    if (term->ldisc)
                        ldisc_send(term->ldisc, term->id_string,
                                   strlen(term->id_string), 0);
                    break;
-                 case 'c':            /* restore power-on settings */
+                 case 'c':            /* RIS: restore power-on settings */
                    compatibility(VT100);
                    power_on(term);
                    if (term->ldisc)   /* cause ldisc to notice changes */
@@ -1841,12 +2020,12 @@ void term_out(Terminal *term)
                    term->disptop = 0;
                    term->seen_disp_event = TRUE;
                    break;
-                 case 'H':            /* set a tab */
+                 case 'H':            /* HTS: set a tab */
                    compatibility(VT100);
                    term->tabs[term->curs.x] = TRUE;
                    break;
 
-                 case ANSI('8', '#'):  /* ESC # 8 fills screen with Es :-) */
+                 case ANSI('8', '#'):  /* DECALN: fills screen with Es :-) */
                    compatibility(VT100);
                    {
                        unsigned long *ldata;
@@ -1877,16 +2056,16 @@ void term_out(Terminal *term)
                        unsigned long nlattr;
                        unsigned long *ldata;
                        switch (ANSI(c, term->esc_query)) {
-                         case ANSI('3', '#'):
+                         case ANSI('3', '#'): /* DECDHL: 2*height, top */
                            nlattr = LATTR_TOP;
                            break;
-                         case ANSI('4', '#'):
+                         case ANSI('4', '#'): /* DECDHL: 2*height, bottom */
                            nlattr = LATTR_BOT;
                            break;
-                         case ANSI('5', '#'):
+                         case ANSI('5', '#'): /* DECSWL: normal */
                            nlattr = LATTR_NORM;
                            break;
-                         default: /* spiritually case ANSI('6', '#'): */
+                         default: /* case ANSI('6', '#'): DECDWL: 2*width */
                            nlattr = LATTR_WIDE;
                            break;
                        }
@@ -1895,7 +2074,7 @@ void term_out(Terminal *term)
                        ldata[term->cols] |= nlattr;
                    }
                    break;
-
+                 /* GZD4: G0 designate 94-set */
                  case ANSI('A', '('):
                    compatibility(VT100);
                    if (!term->cfg.no_remote_charset)
@@ -1916,7 +2095,7 @@ void term_out(Terminal *term)
                    if (!term->cfg.no_remote_charset)
                        term->cset_attr[0] = ATTR_SCOACS; 
                    break;
-
+                 /* G1D4: G1-designate 94-set */
                  case ANSI('A', ')'):
                    compatibility(VT100);
                    if (!term->cfg.no_remote_charset)
@@ -1937,7 +2116,7 @@ void term_out(Terminal *term)
                    if (!term->cfg.no_remote_charset)
                        term->cset_attr[1] = ATTR_SCOACS; 
                    break;
-
+                 /* DOCS: Designate other coding system */
                  case ANSI('8', '%'):  /* Old Linux code */
                  case ANSI('G', '%'):
                    compatibility(OTHER);
@@ -1975,59 +2154,59 @@ void term_out(Terminal *term)
                    term->termstate = SEEN_CSI;
                } else
                    switch (ANSI(c, term->esc_query)) {
-                     case 'A':       /* move up N lines */
+                     case 'A':       /* CUU: move up N lines */
                        move(term, term->curs.x,
                             term->curs.y - def(term->esc_args[0], 1), 1);
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'e':       /* move down N lines */
+                     case 'e':         /* VPR: move down N lines */
                        compatibility(ANSI);
                        /* FALLTHROUGH */
-                     case 'B':
+                     case 'B':         /* CUD: Cursor down */
                        move(term, term->curs.x,
                             term->curs.y + def(term->esc_args[0], 1), 1);
                        term->seen_disp_event = TRUE;
                        break;
-                     case ANSI('c', '>'):      /* report xterm version */
+                     case ANSI('c', '>'):      /* DA: report xterm version */
                        compatibility(OTHER);
                        /* this reports xterm version 136 so that VIM can
                           use the drag messages from the mouse reporting */
                        if (term->ldisc)
                            ldisc_send(term->ldisc, "\033[>0;136;0c", 11, 0);
                        break;
-                     case 'a':       /* move right N cols */
+                     case 'a':         /* HPR: move right N cols */
                        compatibility(ANSI);
                        /* FALLTHROUGH */
-                     case 'C':
+                     case 'C':         /* CUF: Cursor right */ 
                        move(term, term->curs.x + def(term->esc_args[0], 1),
                             term->curs.y, 1);
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'D':       /* move left N cols */
+                     case 'D':       /* CUB: move left N cols */
                        move(term, term->curs.x - def(term->esc_args[0], 1),
                             term->curs.y, 1);
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'E':       /* move down N lines and CR */
+                     case 'E':       /* CNL: move down N lines and CR */
                        compatibility(ANSI);
                        move(term, 0,
                             term->curs.y + def(term->esc_args[0], 1), 1);
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'F':       /* move up N lines and CR */
+                     case 'F':       /* CPL: move up N lines and CR */
                        compatibility(ANSI);
                        move(term, 0,
                             term->curs.y - def(term->esc_args[0], 1), 1);
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'G':
-                     case '`':       /* set horizontal posn */
+                     case 'G':       /* CHA */
+                     case '`':       /* HPA: set horizontal posn */
                        compatibility(ANSI);
                        move(term, def(term->esc_args[0], 1) - 1,
                             term->curs.y, 0);
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'd':       /* set vertical posn */
+                     case 'd':       /* VPA: set vertical posn */
                        compatibility(ANSI);
                        move(term, term->curs.x,
                             ((term->dec_om ? term->marg_t : 0) +
@@ -2035,8 +2214,8 @@ void term_out(Terminal *term)
                             (term->dec_om ? 2 : 0));
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'H':
-                     case 'f':       /* set horz and vert posns at once */
+                     case 'H':      /* CUP */
+                     case 'f':      /* HVP: set horz and vert posns at once */
                        if (term->esc_nargs < 2)
                            term->esc_args[1] = ARG_DEFAULT;
                        move(term, def(term->esc_args[1], 1) - 1,
@@ -2045,7 +2224,7 @@ void term_out(Terminal *term)
                             (term->dec_om ? 2 : 0));
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'J':       /* erase screen or parts of it */
+                     case 'J':       /* ED: erase screen or parts of it */
                        {
                            unsigned int i = def(term->esc_args[0], 0) + 1;
                            if (i > 3)
@@ -2055,7 +2234,7 @@ void term_out(Terminal *term)
                        term->disptop = 0;
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'K':       /* erase line or parts of it */
+                     case 'K':       /* EL: erase line or parts of it */
                        {
                            unsigned int i = def(term->esc_args[0], 0) + 1;
                            if (i > 3)
@@ -2064,7 +2243,7 @@ void term_out(Terminal *term)
                        }
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'L':       /* insert lines */
+                     case 'L':       /* IL: insert lines */
                        compatibility(VT102);
                        if (term->curs.y <= term->marg_b)
                            scroll(term, term->curs.y, term->marg_b,
@@ -2072,7 +2251,7 @@ void term_out(Terminal *term)
                        fix_cpos;
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'M':       /* delete lines */
+                     case 'M':       /* DL: delete lines */
                        compatibility(VT102);
                        if (term->curs.y <= term->marg_b)
                            scroll(term, term->curs.y, term->marg_b,
@@ -2081,25 +2260,25 @@ void term_out(Terminal *term)
                        fix_cpos;
                        term->seen_disp_event = TRUE;
                        break;
-                     case '@':       /* insert chars */
+                     case '@':       /* ICH: insert chars */
                        /* XXX VTTEST says this is vt220, vt510 manual says vt102 */
                        compatibility(VT102);
                        insch(term, def(term->esc_args[0], 1));
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'P':       /* delete chars */
+                     case 'P':       /* DCH: delete chars */
                        compatibility(VT102);
                        insch(term, -def(term->esc_args[0], 1));
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'c':       /* terminal type query */
+                     case 'c':       /* DA: terminal type query */
                        compatibility(VT100);
                        /* This is the response for a VT102 */
                        if (term->ldisc)
                            ldisc_send(term->ldisc, term->id_string,
                                       strlen(term->id_string), 0);
                        break;
-                     case 'n':       /* cursor position query */
+                     case 'n':       /* DSR: cursor position query */
                        if (term->ldisc) {
                            if (term->esc_args[0] == 6) {
                                char buf[32];
@@ -2111,7 +2290,7 @@ void term_out(Terminal *term)
                            }
                        }
                        break;
-                     case 'h':       /* toggle modes to high */
+                     case 'h':       /* SM: toggle modes to high */
                      case ANSI_QUE('h'):
                        compatibility(VT100);
                        {
@@ -2121,7 +2300,7 @@ void term_out(Terminal *term)
                                            term->esc_query, TRUE);
                        }
                        break;
-                     case 'i':
+                     case 'i':         /* MC: Media copy */
                      case ANSI_QUE('i'):
                        compatibility(VT100);
                        {
@@ -2137,7 +2316,7 @@ void term_out(Terminal *term)
                            }
                        }
                        break;                  
-                     case 'l':       /* toggle modes to low */
+                     case 'l':       /* RM: toggle modes to low */
                      case ANSI_QUE('l'):
                        compatibility(VT100);
                        {
@@ -2147,7 +2326,7 @@ void term_out(Terminal *term)
                                            term->esc_query, FALSE);
                        }
                        break;
-                     case 'g':       /* clear tabs */
+                     case 'g':       /* TBC: clear tabs */
                        compatibility(VT100);
                        if (term->esc_nargs == 1) {
                            if (term->esc_args[0] == 0) {
@@ -2159,7 +2338,7 @@ void term_out(Terminal *term)
                            }
                        }
                        break;
-                     case 'r':       /* set scroll margins */
+                     case 'r':       /* DECSTBM: set scroll margins */
                        compatibility(VT100);
                        if (term->esc_nargs <= 2) {
                            int top, bot;
@@ -2193,7 +2372,7 @@ void term_out(Terminal *term)
                            }
                        }
                        break;
-                     case 'm':       /* set graphics rendition */
+                     case 'm':       /* SGR: set graphics rendition */
                        {
                            /* 
                             * A VT100 without the AVO only had one
@@ -2227,7 +2406,7 @@ void term_out(Terminal *term)
                            for (i = 0; i < term->esc_nargs; i++) {
                                switch (def(term->esc_args[i], 0)) {
                                  case 0:       /* restore defaults */
-                                   term->curr_attr = ATTR_DEFAULT;
+                                   term->curr_attr = term->default_attr;
                                    break;
                                  case 1:       /* enable bold */
                                    compatibility(VT100AVO);
@@ -2243,6 +2422,11 @@ void term_out(Terminal *term)
                                    compatibility(VT100AVO);
                                    term->curr_attr |= ATTR_BLINK;
                                    break;
+                                 case 6:       /* SCO light bkgrd */
+                                   compatibility(SCOANSI);
+                                   term->blink_is_real = FALSE;
+                                   term->curr_attr |= ATTR_BLINK;
+                                   break;
                                  case 7:       /* enable reverse video */
                                    term->curr_attr |= ATTR_REVERSE;
                                    break;
@@ -2352,7 +2536,7 @@ void term_out(Terminal *term)
                        save_cursor(term, FALSE);
                        term->seen_disp_event = TRUE;
                        break;
-                     case 't':       /* set page size - ie window height */
+                     case 't': /* DECSLPP: set page size - ie window height */
                        /*
                         * VT340/VT420 sequence DECSLPP, DEC only allows values
                         *  24/25/36/48/72/144 other emulators (eg dtterm) use
@@ -2465,7 +2649,8 @@ void term_out(Terminal *term)
                                 */
                                break;
                              case 20:
-                               if (term->ldisc) {
+                               if (term->ldisc &&
+                                   !term->cfg.no_remote_qtitle) {
                                    p = get_window_title(term->frontend, TRUE);
                                    len = strlen(p);
                                    ldisc_send(term->ldisc, "\033]L", 3, 0);
@@ -2474,7 +2659,8 @@ void term_out(Terminal *term)
                                }
                                break;
                              case 21:
-                               if (term->ldisc) {
+                               if (term->ldisc &&
+                                   !term->cfg.no_remote_qtitle) {
                                    p = get_window_title(term->frontend,FALSE);
                                    len = strlen(p);
                                    ldisc_send(term->ldisc, "\033]l", 3, 0);
@@ -2485,7 +2671,7 @@ void term_out(Terminal *term)
                            }
                        }
                        break;
-                     case 'S':
+                     case 'S':         /* SU: Scroll up */
                        compatibility(SCOANSI);
                        scroll(term, term->marg_t, term->marg_b,
                               def(term->esc_args[0], 1), TRUE);
@@ -2493,7 +2679,7 @@ void term_out(Terminal *term)
                        term->wrapnext = FALSE;
                        term->seen_disp_event = TRUE;
                        break;
-                     case 'T':
+                     case 'T':         /* SD: Scroll down */
                        compatibility(SCOANSI);
                        scroll(term, term->marg_t, term->marg_b,
                               -def(term->esc_args[0], 1), TRUE);
@@ -2501,11 +2687,12 @@ void term_out(Terminal *term)
                        term->wrapnext = FALSE;
                        term->seen_disp_event = TRUE;
                        break;
-                     case ANSI('|', '*'):
-                       /* VT420 sequence DECSNLS
+                     case ANSI('|', '*'): /* DECSNLS */
+                       /* 
                         * Set number of lines on screen
-                        * VT420 uses VGA like hardware and can support any size in
-                        * reasonable range (24..49 AIUI) with no default specified.
+                        * VT420 uses VGA like hardware and can
+                        * support any size in reasonable range
+                        * (24..49 AIUI) with no default specified.
                         */
                        compatibility(VT420);
                        if (term->esc_nargs == 1 && term->esc_args[0] > 0) {
@@ -2516,10 +2703,11 @@ void term_out(Terminal *term)
                            deselect(term);
                        }
                        break;
-                     case ANSI('|', '$'):
-                       /* VT340/VT420 sequence DECSCPP
+                     case ANSI('|', '$'): /* DECSCPP */
+                       /*
                         * Set number of columns per page
-                        * Docs imply range is only 80 or 132, but I'll allow any.
+                        * Docs imply range is only 80 or 132, but
+                        * I'll allow any.
                         */
                        compatibility(VT340TEXT);
                        if (term->esc_nargs <= 1) {
@@ -2530,8 +2718,9 @@ void term_out(Terminal *term)
                            deselect(term);
                        }
                        break;
-                     case 'X':       /* write N spaces w/o moving cursor */
-                       /* XXX VTTEST says this is vt220, vt510 manual says vt100 */
+                     case 'X':     /* ECH: write N spaces w/o moving cursor */
+                       /* XXX VTTEST says this is vt220, vt510 manual
+                        * says vt100 */
                        compatibility(ANSIMIN);
                        {
                            int n = def(term->esc_args[0], 1);
@@ -2549,7 +2738,7 @@ void term_out(Terminal *term)
                            term->seen_disp_event = TRUE;
                        }
                        break;
-                     case 'x':       /* report terminal characteristics */
+                     case 'x':       /* DECREQTPARM: report terminal characteristics */
                        compatibility(VT100);
                        if (term->ldisc) {
                            char buf[32];
@@ -2561,7 +2750,7 @@ void term_out(Terminal *term)
                            }
                        }
                        break;
-                     case 'Z':         /* BackTab for xterm */
+                     case 'Z':         /* CBT: BackTab for xterm */
                        compatibility(OTHER);
                        {
                            int i = def(term->esc_args[0], 1);
@@ -2577,8 +2766,77 @@ void term_out(Terminal *term)
                            check_selection(term, old_curs, term->curs);
                        }
                        break;
+                     case ANSI('c', '='):      /* Hide or Show Cursor */
+                       compatibility(SCOANSI);
+                       switch(term->esc_args[0]) {
+                         case 0:  /* hide cursor */
+                           term->cursor_on = FALSE;
+                           break;
+                         case 1:  /* restore cursor */
+                           term->big_cursor = FALSE;
+                           term->cursor_on = TRUE;
+                           break;
+                         case 2:  /* block cursor */
+                           term->big_cursor = TRUE;
+                           term->cursor_on = TRUE;
+                           break;
+                       }
+                       break;
+                     case ANSI('C', '='):
+                       /*
+                        * set cursor start on scanline esc_args[0] and
+                        * end on scanline esc_args[1].If you set
+                        * the bottom scan line to a value less than
+                        * the top scan line, the cursor will disappear.
+                        */
+                       compatibility(SCOANSI);
+                       if (term->esc_nargs >= 2) {
+                           if (term->esc_args[0] > term->esc_args[1])
+                               term->cursor_on = FALSE;
+                           else
+                               term->cursor_on = TRUE;
+                       }
+                       break;
+                     case ANSI('D', '='):
+                       compatibility(SCOANSI);
+                       term->blink_is_real = FALSE;
+                       if (term->esc_args[0]>=1)
+                           term->curr_attr |= ATTR_BLINK;
+                       else
+                           term->curr_attr &= ~ATTR_BLINK;
+                       break;
+                     case ANSI('E', '='):
+                       compatibility(SCOANSI);
+                       term->blink_is_real = (term->esc_args[0] >= 1);
+                       break;
+                     case ANSI('F', '='):      /* set normal foreground */
+                       compatibility(SCOANSI);
+                       if (term->esc_args[0] >= 0 && term->esc_args[0] < 16) {
+                           long colour =
+                               (sco2ansicolour[term->esc_args[0] & 0x7] |
+                                ((term->esc_args[0] & 0x8) << 1)) <<
+                               ATTR_FGSHIFT;
+                           term->curr_attr &= ~ATTR_FGMASK;
+                           term->curr_attr |= colour;
+                           term->default_attr &= ~ATTR_FGMASK;
+                           term->default_attr |= colour;
+                       }
+                       break;
+                     case ANSI('G', '='):      /* set normal background */
+                       compatibility(SCOANSI);
+                       if (term->esc_args[0] >= 0 && term->esc_args[0] < 16) {
+                           long colour =
+                               (sco2ansicolour[term->esc_args[0] & 0x7] |
+                                ((term->esc_args[0] & 0x8) << 1)) <<
+                               ATTR_BGSHIFT;
+                           term->curr_attr &= ~ATTR_BGMASK;
+                           term->curr_attr |= colour;
+                           term->default_attr &= ~ATTR_BGMASK;
+                           term->default_attr |= colour;
+                       }
+                       break;
                      case ANSI('L', '='):
-                       compatibility(OTHER);
+                       compatibility(SCOANSI);
                        term->use_bce = (term->esc_args[0] <= 0);
                        term->erase_char = ERASE_CHAR;
                        if (term->use_bce)
@@ -2586,11 +2844,7 @@ void term_out(Terminal *term)
                                                (term->curr_attr & 
                                                 (ATTR_FGMASK | ATTR_BGMASK)));
                        break;
-                     case ANSI('E', '='):
-                       compatibility(OTHER);
-                       term->blink_is_real = (term->esc_args[0] >= 1);
-                       break;
-                     case ANSI('p', '"'):
+                     case ANSI('p', '"'): /* DECSCL: set compat level */
                        /*
                         * Allow the host to make this emulator a
                         * 'perfect' VT102. This first appeared in
@@ -3076,17 +3330,73 @@ static int linecmp(Terminal *term, unsigned long *a, unsigned long *b)
 #endif
 
 /*
+ * To prevent having to run the reasonably tricky bidi algorithm
+ * too many times, we maintain a cache of the last lineful of data
+ * fed to the algorithm on each line of the display.
+ */
+static int term_bidi_cache_hit(Terminal *term, int line,
+                              unsigned long *lbefore, int width)
+{
+    if (!term->pre_bidi_cache)
+       return FALSE;                  /* cache doesn't even exist yet! */
+
+    if (line >= term->bidi_cache_size)
+       return FALSE;                  /* cache doesn't have this many lines */
+
+    if (!term->pre_bidi_cache[line])
+       return FALSE;                  /* cache doesn't contain _this_ line */
+
+    if (!memcmp(term->pre_bidi_cache[line], lbefore,
+               width * sizeof(unsigned long)))
+       return TRUE;                   /* aha! the line matches the cache */
+
+    return FALSE;                     /* it didn't match. */
+}
+
+static void term_bidi_cache_store(Terminal *term, int line,
+                                 unsigned long *lbefore,
+                                 unsigned long *lafter, int width)
+{
+    if (!term->pre_bidi_cache || term->bidi_cache_size <= line) {
+       int j = term->bidi_cache_size;
+       term->bidi_cache_size = line+1;
+       term->pre_bidi_cache = sresize(term->pre_bidi_cache,
+                                      term->bidi_cache_size,
+                                      unsigned long *);
+       term->post_bidi_cache = sresize(term->post_bidi_cache,
+                                       term->bidi_cache_size,
+                                       unsigned long *);
+       while (j < term->bidi_cache_size) {
+           term->pre_bidi_cache[j] = term->post_bidi_cache[j] = NULL;
+           j++;
+       }
+    }
+
+    sfree(term->pre_bidi_cache[line]);
+    sfree(term->post_bidi_cache[line]);
+
+    term->pre_bidi_cache[line] = snewn(width, unsigned long);
+    term->post_bidi_cache[line] = snewn(width, unsigned long);
+
+    memcpy(term->pre_bidi_cache[line], lbefore, width * sizeof(unsigned long));
+    memcpy(term->post_bidi_cache[line], lafter, width * sizeof(unsigned long));
+}
+
+/*
  * Given a context, update the window. Out of paranoia, we don't
  * allow WM_PAINT responses to do scrolling optimisations.
  */
 static void do_paint(Terminal *term, Context ctx, int may_optimise)
 {
-    int i, j, our_curs_y, our_curs_x;
+    int i, it, j, our_curs_y, our_curs_x;
     unsigned long rv, cursor;
     pos scrpos;
     char ch[1024];
     long cursor_background = ERASE_CHAR;
     unsigned long ticks;
+#ifdef OPTIMISE_SCROLL
+    struct scrollregion *sr;
+#endif /* OPTIMISE_SCROLL */
 
     /*
      * Check the visual bell state.
@@ -3094,8 +3404,8 @@ static void do_paint(Terminal *term, Context ctx, int may_optimise)
     if (term->in_vbell) {
        ticks = GETTICKCOUNT();
        if (ticks - term->vbell_startpoint >= VBELL_TIMEOUT)
-           term->in_vbell = FALSE; 
-   }
+           term->in_vbell = FALSE;
+    }
 
     rv = (!term->rvideo ^ !term->in_vbell ? ATTR_REVERSE : 0);
 
@@ -3149,6 +3459,18 @@ static void do_paint(Terminal *term, Context ctx, int may_optimise)
     }
     term->dispcurs = NULL;
 
+#ifdef OPTIMISE_SCROLL
+    /* Do scrolls */
+    sr = term->scrollhead;
+    while (sr) {
+       struct scrollregion *next = sr->next;
+       do_scroll(ctx, sr->topline, sr->botline, sr->lines);
+       sfree(sr);
+       sr = next;
+    }
+    term->scrollhead = term->scrolltail = NULL;
+#endif /* OPTIMISE_SCROLL */
+
     /* The normal screen data */
     for (i = 0; i < term->rows; i++) {
        unsigned long *ldata;
@@ -3169,6 +3491,67 @@ static void do_paint(Terminal *term, Context ctx, int may_optimise)
                                  term->disptext[idx + term->cols]);
        term->disptext[idx + term->cols] = ldata[term->cols];
 
+       /* Do Arabic shaping and bidi. */
+       if(!term->cfg.bidi || !term->cfg.arabicshaping) {
+
+           if (!term_bidi_cache_hit(term, i, ldata, term->cols)) {
+
+               for(it=0; it<term->cols ; it++)
+               {
+                   int uc = (ldata[it] & 0xFFFF);
+
+                   switch (uc & CSET_MASK) {
+                     case ATTR_LINEDRW:
+                       if (!term->cfg.rawcnp) {
+                           uc = term->ucsdata->unitab_xterm[uc & 0xFF];
+                           break;
+                       }
+                     case ATTR_ASCII:
+                       uc = term->ucsdata->unitab_line[uc & 0xFF];
+                       break;
+                     case ATTR_SCOACS:
+                       uc = term->ucsdata->unitab_scoacs[uc&0xFF];
+                       break;
+                   }
+                   switch (uc & CSET_MASK) {
+                     case ATTR_ACP:
+                       uc = term->ucsdata->unitab_font[uc & 0xFF];
+                       break;
+                     case ATTR_OEMCP:
+                       uc = term->ucsdata->unitab_oemcp[uc & 0xFF];
+                       break;
+                   }
+
+                   term->wcFrom[it].origwc = term->wcFrom[it].wc = uc;
+                   term->wcFrom[it].index = it;
+               }
+
+               if(!term->cfg.bidi)
+                   do_bidi(term->wcFrom, term->cols);
+
+               /* this is saved iff done from inside the shaping */
+               if(!term->cfg.bidi && term->cfg.arabicshaping)
+                   for(it=0; it<term->cols; it++)
+                       term->wcTo[it] = term->wcFrom[it];
+
+               if(!term->cfg.arabicshaping)
+                   do_shape(term->wcFrom, term->wcTo, term->cols);
+
+               for(it=0; it<term->cols ; it++)
+               {
+                   term->ltemp[it] = ldata[term->wcTo[it].index];
+
+                   if (term->wcTo[it].origwc != term->wcTo[it].wc)
+                       term->ltemp[it] = ((term->ltemp[it] & 0xFFFF0000) |
+                                          term->wcTo[it].wc);
+               }
+               term_bidi_cache_store(term, i, ldata, term->ltemp, term->cols);
+               ldata = term->ltemp;
+           } else {
+               ldata = term->post_bidi_cache[i];
+           }
+       }
+
        for (j = 0; j < term->cols; j++, idx++) {
            unsigned long tattr, tchar;
            unsigned long *d = ldata + j;
@@ -3381,7 +3764,7 @@ void term_paint(Terminal *term, Context ctx,
  */
 void term_scroll(Terminal *term, int rel, int where)
 {
-    int sbtop = -count234(term->scrollback);
+    int sbtop = -sblines(term);
 #ifdef OPTIMISE_SCROLL
     int olddisptop = term->disptop;
     int shift;
@@ -3401,7 +3784,7 @@ void term_scroll(Terminal *term, int rel, int where)
     term_update(term);
 }
 
-static void clipme(Terminal *term, pos top, pos bottom, int rect)
+static void clipme(Terminal *term, pos top, pos bottom, int rect, int desel)
 {
     wchar_t *workbuf;
     wchar_t *wbptr;                   /* where next char goes within workbuf */
@@ -3410,7 +3793,7 @@ static void clipme(Terminal *term, pos top, pos bottom, int rect)
     int buflen;                               /* amount of memory allocated to workbuf */
 
     buflen = 5120;                    /* Default size */
-    workbuf = smalloc(buflen * sizeof(wchar_t));
+    workbuf = snewn(buflen, wchar_t);
     wbptr = workbuf;                  /* start filling here */
     old_top_x = top.x;                /* needed for rect==1 */
 
@@ -3526,9 +3909,8 @@ static void clipme(Terminal *term, pos top, pos bottom, int rect)
            for (p = cbuf; *p; p++) {
                /* Enough overhead for trailing NL and nul */
                if (wblen >= buflen - 16) {
-                   workbuf =
-                       srealloc(workbuf,
-                                sizeof(wchar_t) * (buflen += 100));
+                   buflen += 100;
+                   workbuf = sresize(workbuf, buflen, wchar_t);
                    wbptr = workbuf + wblen;
                }
                wblen++;
@@ -3550,7 +3932,7 @@ static void clipme(Terminal *term, pos top, pos bottom, int rect)
     wblen++;
     *wbptr++ = 0;
 #endif
-    write_clip(term->frontend, workbuf, wblen, FALSE); /* transfer to clipbd */
+    write_clip(term->frontend, workbuf, wblen, desel); /* transfer to clipbd */
     if (buflen > 0)                   /* indicates we allocated this buffer */
        sfree(workbuf);
 }
@@ -3558,9 +3940,13 @@ static void clipme(Terminal *term, pos top, pos bottom, int rect)
 void term_copyall(Terminal *term)
 {
     pos top;
-    top.y = -count234(term->scrollback);
+    pos bottom;
+    tree234 *screen = term->screen;
+    top.y = -sblines(term);
     top.x = 0;
-    clipme(term, top, term->curs, 0);
+    bottom.y = find_last_nonempty_line(term, screen);
+    bottom.x = term->cols;
+    clipme(term, top, bottom, 0, TRUE);
 }
 
 /*
@@ -3685,7 +4071,7 @@ static pos sel_spread_half(Terminal *term, pos p, int dir)
 {
     unsigned long *ldata;
     short wvalue;
-    int topy = -count234(term->scrollback);
+    int topy = -sblines(term);
 
     ldata = lineptr(p.y);
 
@@ -3797,7 +4183,7 @@ void term_do_paste(Terminal *term)
         if (term->paste_buffer)
             sfree(term->paste_buffer);
         term->paste_pos = term->paste_hold = term->paste_len = 0;
-        term->paste_buffer = smalloc(len * sizeof(wchar_t));
+        term->paste_buffer = snewn(len, wchar_t);
 
         p = q = data;
         while (p < data + len) {
@@ -4025,7 +4411,7 @@ void term_mouse(Terminal *term, Mouse_Button braw, Mouse_Button bcooked,
             * data to the clipboard.
             */
            clipme(term, term->selstart, term->selend,
-                  (term->seltype == RECTANGULAR));
+                  (term->seltype == RECTANGULAR), FALSE);
            term->selstate = SELECTED;
        } else
            term->selstate = NO_SELECTION;
@@ -4052,7 +4438,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
 
     fprintf(stderr, "keysym = %d, %d chars:", keysym, tlen);
     for (i = 0; i < tlen; i++)
-       fprintf(stderr, " %04x", text[i]);
+       fprintf(stderr, " %04x", (unsigned)text[i]);
     fprintf(stderr, "\n");
 #endif
 
@@ -4101,8 +4487,8 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
     if (keysym == PK_NULL && (modifiers & PKM_CONTROL) && tlen == 1 &&
        text[0] >= 0x20 && text[0] <= 0x7e) {
        /* ASCII chars + Control */
-       if (text[0] >= 0x40 && text[0] <= 0x5f ||
-           text[0] >= 0x61 && text[0] <= 0x7a)
+       if ((text[0] >= 0x40 && text[0] <= 0x5f) ||
+           (text[0] >= 0x61 && text[0] <= 0x7a))
            text[0] &= 0x1f;
        else {
            /*
@@ -4141,6 +4527,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
          case PK_KP7: c = 'y'; break;
          case PK_KP8: c = 'k'; break;
          case PK_KP9: c = 'u'; break;
+         default: break; /* else gcc warns `enum value not used' */
        }
        if (c != 0) {
            if (c != '.') {
@@ -4171,6 +4558,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
              case PK_PF2: xkey = 'Q'; break;
              case PK_PF3: xkey = 'R'; break;
              case PK_PF4: xkey = 'S'; break;
+             default: break; /* else gcc warns `enum value not used' */
            }
        }
        if (term->app_keypad_keys && !term->cfg.no_applic_k) {
@@ -4187,6 +4575,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
              case PK_KP9: xkey = 'y'; break;
              case PK_KPDECIMAL: xkey = 'n'; break;
              case PK_KPENTER: xkey = 'M'; break;
+             default: break; /* else gcc warns `enum value not used' */
            }
            if (term->cfg.funky_type == FUNKY_XTERM && tlen > 0) {
                /*
@@ -4221,6 +4610,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
                    break;
                  case PK_KPMINUS: xkey = 'm'; break;
                  case PK_KPCOMMA: xkey = 'l'; break;
+                 default: break; /* else gcc warns `enum value not used' */
                }
            }
        }
@@ -4247,6 +4637,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
              case PK_KP7: keysym = PK_HOME; break;
              case PK_KP8: keysym = PK_UP; break;
              case PK_KP9: keysym = PK_PAGEUP; break;
+             default: break; /* else gcc warns `enum value not used' */
            }
        }
     }
@@ -4285,6 +4676,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
                *p++ = 0x0a;
            goto done;
        }
+      default: break; /* else gcc warns `enum value not used' */
     }
 
     /* SCO function keys and editing keys */
@@ -4309,6 +4701,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
              case PK_END:      xkey = 'F'; break;
              case PK_PAGEUP:   xkey = 'I'; break;
              case PK_PAGEDOWN: xkey = 'G'; break;
+             default: break; /* else gcc warns `enum value not used' */
            }
            p += sprintf((char *) p, "\x1B[%c", xkey);
        }
@@ -4326,6 +4719,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
              case PK_END:      keysym = PK_PAGEUP;   break;
              case PK_PAGEUP:   keysym = PK_DELETE;   break;
              case PK_PAGEDOWN: keysym = PK_PAGEDOWN; break;
+             default: break; /* else gcc warns `enum value not used' */
            }
        }
 
@@ -4350,6 +4744,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
              case PK_END:      xkey = 'E'; break;
              case PK_PAGEUP:   xkey = 'I'; break;
              case PK_PAGEDOWN: xkey = 'G'; break;
+             default: xkey=0; break; /* else gcc warns `enum value not used'*/
            }
            p += sprintf((char *) p, "\x1B%c", xkey);
            goto done;
@@ -4362,6 +4757,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
          case PK_END:      code = 4; break;
          case PK_PAGEUP:   code = 5; break;
          case PK_PAGEDOWN: code = 6; break;
+         default: code = 0; break; /* else gcc warns `enum value not used' */
        }
        p += sprintf((char *) p, "\x1B[%d~", code);
        goto done;
@@ -4405,6 +4801,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
          case PK_RIGHT: xkey = 'C'; break;
          case PK_LEFT:  xkey = 'D'; break;
          case PK_REST:  xkey = 'G'; break; /* centre key on number pad */
+         default: xkey = 0; break; /* else gcc warns `enum value not used' */
        }
        if (term->vt52_mode)
            p += sprintf((char *) p, "\x1B%c", xkey);
@@ -4462,7 +4859,7 @@ void term_key(Terminal *term, Key_Sym keysym, wchar_t *text, size_t tlen,
 #if 0
            fprintf(stderr, "sending %d unichars:", tlen);
            for (i = 0; i < tlen; i++)
-               fprintf(stderr, " %04x", text[i]);
+               fprintf(stderr, " %04x", (unsigned) text[i]);
            fprintf(stderr, "\n");
 #endif
            luni_send(term->ldisc, text, tlen, 1);
@@ -4541,17 +4938,17 @@ int term_ldisc(Terminal *term, int option)
     return FALSE;
 }
 
-/*
- * from_backend(), to get data from the backend for the terminal.
- */
-int from_backend(void *vterm, int is_stderr, char *data, int len)
+int term_data(Terminal *term, int is_stderr, const char *data, int len)
 {
-    Terminal *term = (Terminal *)vterm;
-
-    assert(len > 0);
-
     bufchain_add(&term->inbuf, data, len);
 
+    if (!term->in_term_out) {
+       term->in_term_out = TRUE;
+       term_blink(term, 1);
+       term_out(term);
+       term->in_term_out = FALSE;
+    }
+
     /*
      * term_out() always completely empties inbuf. Therefore,
      * there's no reason at all to return anything other than zero