[PATCH] GtkText fixes

[Owen Taylor <owt1 cornell edu>]

This patch fixes the two problems reported by Stefan Jeske,
and incorporates Tony Gale's change; it also includes some
extra sanity checks for the Text and Entry widget.

(Would somebody who has a decent connection to va.debian.org
 commit this? If not, I'll try late tonight, when things
 seem to get better.)

[ The ChangeLog chunk also includes another patch which I'll
  post separately ]

*** gtk+0.99.5/ChangeLog	Mon Mar  9 23:45:53 1998
--- gtk+/ChangeLog	Tue Mar 10 13:35:38 1998
***************
*** 1,3 ****
--- 1,17 ----
+ Tue Mar 10 13:34:29 1998  Owen Taylor  <owt1@cornell.edu>
+ 
+ 	* gtk/gtkrange.c (gtk_range_default_[vh]trough_click): 
+ 	  Take forward/back step arrows into account when computing
+ 	  position for middle button clicks.
+ 
+ 	* gtk/gtktext.c gtk/gtkentry.c:
+ 	  - Fixes for deleting characters (don't subtract guints and get
+ 	    negative numbers!)
+ 	  - Reset cursor_virtual_x when moving by words and lines
+ 	  - Extra sanity checks
+ 	  - Fix to gtk_text_get_chars 
+ 	         (from Tony Gale <gale@daedalus.dera.gov.uk>)
+ 
  Tue Mar 10 05:42:34 1998  Tim Janik  <timj@gimp.org>
  
          * configure.in: Bumped version number to 0.99.5.
--- gtk+CVS-2/gtk/gtktext.c	Mon Mar  9 22:22:06 1998
+++ gtk+/gtk/gtktext.c	Tue Mar 10 12:06:33 1998
@@ -781,7 +781,7 @@
 
   if (text->point.index < text->first_line_start_index)
     {
-      if (text->point.index >= text->first_line_start_index - nchars)
+      if (text->point.index + nchars >= text->first_line_start_index)
 	{
 	  text->first_line_start_index = text->point.index;
 	  while ((text->first_line_start_index > 0) &&
@@ -794,13 +794,15 @@
     }
 
   if (text->point.index < editable->selection_start_pos)
-    editable->selection_start_pos -= nchars;
+    editable->selection_start_pos -= 
+      MIN(nchars, editable->selection_start_pos - text->point.index);
   if (text->point.index < editable->selection_end_pos)
-    editable->selection_end_pos -= nchars;
+    editable->selection_end_pos -= 
+      MIN(nchars, editable->selection_end_pos - text->point.index);
   /* We'll reset the cursor later anyways if we aren't frozen */
   if (text->point.index < text->cursor_mark.index)
-    text->cursor_mark.index -= nchars;
-
+    text->cursor_mark.index -=
+      MIN(nchars, text->cursor_mark.index - text->point.index);
 
   move_gap_to_point (text);
 
@@ -828,14 +830,14 @@
   gchar *p;
   guint n, nchars;
 
-  if (end_pos < 0)
-    end_pos = TEXT_LENGTH (text);
-  
   g_return_val_if_fail (editable != NULL, NULL);
   g_return_val_if_fail (GTK_IS_TEXT (editable), NULL);
   text = GTK_TEXT (editable);
   
-  if (end_pos > TEXT_LENGTH (text))
+  if (end_pos < 0)
+    end_pos = TEXT_LENGTH (text);
+  
+  if ((end_pos > TEXT_LENGTH (text)) || (end_pos < start_pos))
     return NULL;
 
   nchars = end_pos - start_pos;
@@ -1585,7 +1587,8 @@
   if (end_pos < 0)
     end_pos = TEXT_LENGTH (text);
   
-  gtk_text_forward_delete (text, end_pos - start_pos);
+  if (end_pos > start_pos)
+    gtk_text_forward_delete (text, end_pos - start_pos);
 }
 
 static gint
@@ -2033,10 +2036,14 @@
 fetch_lines_backward (GtkText* text)
 {
   GList* new_lines = NULL, *new_line_start;
+  GtkPropertyMark mark;
+
+  if (CACHE_DATA(text->line_start_cache).start.index == 0)
+    return;
 
-  GtkPropertyMark mark = find_this_line_start_mark (text,
-						 CACHE_DATA(text->line_start_cache).start.index - 1,
-						 &CACHE_DATA(text->line_start_cache).start);
+  mark = find_this_line_start_mark (text,
+				    CACHE_DATA(text->line_start_cache).start.index - 1,
+				    &CACHE_DATA(text->line_start_cache).start);
 
   new_line_start = new_lines = fetch_lines (text, &mark, NULL, FetchLinesCount, 1);
 
@@ -2092,7 +2099,7 @@
       if (line == text->current_line)
 	chars_left -= CACHE_DATA(line).end.index - text->point.index + 1;
       else
-	chars_left -= CACHE_DATA(line).end.index -CACHE_DATA(line).start.index + 1;
+	chars_left -= CACHE_DATA(line).end.index - CACHE_DATA(line).start.index + 1;
 
       if (!text->line_wrap || !CACHE_DATA(line).wraps)
 	*lines += 1;
@@ -2591,7 +2598,7 @@
 	  forward_prop->length += len;
 	}
       else if ((MARK_NEXT_LIST_PTR(mark) == NULL) &&
-	       (MARK_OFFSET(mark) == forward_prop->length - 1))
+	       (MARK_OFFSET(mark) + 1 == forward_prop->length))
 	{
 	  /* Inserting before only the last position in the text */
 	  
@@ -3306,6 +3313,8 @@
 static void
 gtk_text_move_forward_word (GtkText *text)
 {
+  text->cursor_virtual_x = 0;
+
   undraw_cursor (text, FALSE);
   
   while (!LAST_INDEX (text, text->cursor_mark) && 
@@ -3323,6 +3332,8 @@
 static void
 gtk_text_move_backward_word (GtkText *text)
 {
+  text->cursor_virtual_x = 0;
+
   undraw_cursor (text, FALSE);
   
   while ((text->cursor_mark.index > 0) &&
@@ -3340,6 +3351,8 @@
 static void
 gtk_text_move_beginning_of_line (GtkText *text)
 {
+  text->cursor_virtual_x = 0;
+
   undraw_cursor (text, FALSE);
   
   while ((text->cursor_mark.index > 0) &&
@@ -3353,6 +3366,8 @@
 static void
 gtk_text_move_end_of_line (GtkText *text)
 {
+  text->cursor_virtual_x = 0;
+
   undraw_cursor (text, FALSE);
 
   while (!LAST_INDEX (text, text->cursor_mark) &&
@@ -4453,10 +4468,13 @@
   GdkRectangle area;
   gint width;
   gint height;
- 
+
   if (end_pos < 0)
     end_pos = TEXT_LENGTH (text);
 
+  if (end_pos < start_pos)
+    return;
+  
   gdk_window_get_size (text->text_area, &width, &height);
   area.x = 0;
   area.y = -1;
--- gtk+CVS-2/gtk/gtkentry.c	Mon Mar  9 22:21:58 1998
+++ gtk+/gtk/gtkentry.c	Tue Mar 10 12:17:55 1998
@@ -1424,9 +1424,12 @@
     new_text_length = entry->text_max_length - entry->text_length;
 
   /* Don't insert anything, if there was nothing to insert. */
-  if (new_text_length <= 0)
+  if (new_text_length == 0)
     return;
 
+  if (new_text_length < 0)
+    new_text_length = strlen (new_text);
+
   start_pos = *position;
   end_pos = start_pos + new_text_length;
   last_pos = new_text_length + entry->text_length;
@@ -1523,14 +1526,19 @@
   start_pos = MIN(entry->text_length, start_pos);
   end_pos = MIN(entry->text_length, end_pos);
 
-  c = entry->text[end_pos];
-  entry->text[end_pos] = '\0';
-
-  retval = g_strdup (&entry->text[start_pos]);
-
-  entry->text[end_pos] = c;
-
-  return retval;
+  if (start_pos <= end_pos)
+    {
+      c = entry->text[end_pos];
+      entry->text[end_pos] = '\0';
+      
+      retval = g_strdup (&entry->text[start_pos]);
+      
+      entry->text[end_pos] = c;
+      
+      return retval;
+    }
+  else
+    return NULL;
 }
 
 static void