X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/8ceabe903d3305c0a14836a2b021e92bfbf4a429..3d88e64dfcf5dc0fd361ce0c504c67a9196ce44c:/terminal.c

diff --git a/terminal.c b/terminal.c
index 7a21eeed..362d8b58 100644
--- a/terminal.c
+++ b/terminal.c
@@ -99,7 +99,7 @@ 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 +110,19 @@ 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 +137,19 @@ 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);
 
@@ -331,6 +355,8 @@ 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 +372,7 @@ 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 +400,8 @@ 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;
@@ -381,6 +409,9 @@ 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;
@@ -443,6 +474,7 @@ 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 +484,14 @@ 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 +499,69 @@ 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 + 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 +574,20 @@ 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 +624,25 @@ 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 +664,7 @@ 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 +722,7 @@ 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 +769,14 @@ 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 +797,9 @@ 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;
@@ -795,6 +875,35 @@ 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 +929,7 @@ 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 +1051,7 @@ 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 +1081,44 @@ 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;
 }
 
 /*
@@ -1047,6 +1181,10 @@ static void toggle_mode(Terminal *term, int mode, int query, int state)
 	    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 */
 	    /*
@@ -1493,7 +1631,7 @@ 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)
@@ -3087,6 +3225,9 @@ static void do_paint(Terminal *term, Context ctx, int may_optimise)
     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.
@@ -3149,6 +3290,18 @@ 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;
@@ -3381,7 +3534,7 @@ 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;
@@ -3410,7 +3563,7 @@ 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 +3679,8 @@ 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++;
@@ -3558,7 +3710,7 @@ static void clipme(Terminal *term, pos top, pos bottom, int rect)
 void term_copyall(Terminal *term)
 {
     pos top;
-    top.y = -count234(term->scrollback);
+    top.y = -sblines(term);
     top.x = 0;
     clipme(term, top, term->curs, 0);
 }
@@ -3685,7 +3837,7 @@ 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 +3949,7 @@ 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) {
@@ -4052,7 +4204,7 @@ 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 +4253,8 @@ 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 +4293,7 @@ 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 +4324,7 @@ 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 +4341,7 @@ 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 +4376,7 @@ 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 +4403,7 @@ 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 +4442,7 @@ 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 +4467,7 @@ 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 +4485,7 @@ 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 +4510,7 @@ 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: break; /* else gcc warns `enum value not used' */
 	    }
 	    p += sprintf((char *) p, "\x1B%c", xkey);
 	    goto done;
@@ -4362,6 +4523,7 @@ 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: break; /* else gcc warns `enum value not used' */
 	}
 	p += sprintf((char *) p, "\x1B[%d~", code);
 	goto done;
@@ -4405,6 +4567,7 @@ 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: break; /* else gcc warns `enum value not used' */
 	}
 	if (term->vt52_mode)
 	    p += sprintf((char *) p, "\x1B%c", xkey);
@@ -4462,7 +4625,7 @@ 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);
@@ -4544,7 +4707,7 @@ int term_ldisc(Terminal *term, int option)
 /*
  * from_backend(), to get data from the backend for the terminal.
  */
-int from_backend(void *vterm, int is_stderr, char *data, int len)
+int from_backend(void *vterm, int is_stderr, const char *data, int len)
 {
     Terminal *term = (Terminal *)vterm;