Made the undo system robust against the currently pushed undo being too

2004-07-07  Michael Natterer  <mitch@gimp.org>

	Made the undo system robust against the currently pushed undo
	being too large according to prefs settings. Fixes bug #145379.

	* app/core/gimpimage-undo.[ch] (gimp_image_undo_push_undo)
	(gimp_image_undo_group_end): emit "undo-event" *before* calling
	gimp_image_undo_free_space() so the undo history doesn't try to
	remove an item that has never been added.

	(gimp_image_undo_push_undo): added boolean return value indicating
	if the undo could be pushed (FALSE means the undo was to large
	and was discarded right away).

	(gimp_image_undo_push_item): return NULL if the above returned
	FALSE.

	* app/core/gimpimage-undo-push.c (gimp_image_undo_push_text_layer):
	changed accordingly.

ChangeLog

@@ -1,3 +1,23 @@
+2004-07-07  Michael Natterer  <mitch@gimp.org>
+
+	Made the undo system robust against the currently pushed undo
+	being too large according to prefs settings. Fixes bug #145379.
+
+	* app/core/gimpimage-undo.[ch] (gimp_image_undo_push_undo)
+	(gimp_image_undo_group_end): emit "undo-event" *before* calling
+	gimp_image_undo_free_space() so the undo history doesn't try to
+	remove an item that has never been added.
+
+	(gimp_image_undo_push_undo): added boolean return value indicating
+	if the undo could be pushed (FALSE means the undo was to large
+	and was discarded right away).
+
+	(gimp_image_undo_push_item): return NULL if the above returned
+	FALSE.
+
+	* app/core/gimpimage-undo-push.c (gimp_image_undo_push_text_layer):
+	changed accordingly.
+
 2004-07-07  Manish Singh  <yosh@gimp.org>
 
 	* plug-ins/common/jpeg.c: Don't try to load EXIF data if any warnings

app/core/gimpimage-undo-push.c

@@ -1762,9 +1762,7 @@ gimp_image_undo_push_text_layer (GimpImage        *gimage,
 
   undo = gimp_text_undo_new (layer, pspec, undo_desc);
 
-  gimp_image_undo_push_undo (gimage, undo);
-
-  return TRUE;
+  return gimp_image_undo_push_undo (gimage, undo);
 }
 
 

app/core/gimpimage-undo.c

@@ -170,13 +170,13 @@ gimp_image_undo_group_end (GimpImage *gimage)
     {
       gimage->pushing_undo_group = GIMP_UNDO_GROUP_NONE;
 
-      gimp_image_undo_free_space (gimage);
-
       /* Do it here, since undo_push doesn't emit this event while in
        * the middle of a group
        */
       gimp_image_undo_event (gimage, GIMP_UNDO_EVENT_UNDO_PUSHED,
                              gimp_undo_stack_peek (gimage->undo_stack));
+
+      gimp_image_undo_free_space (gimage);
     }
 
   return TRUE;
@@ -245,19 +245,20 @@ gimp_image_undo_push_item (GimpImage        *gimage,
                             pop_func, free_func);
     }
 
-  gimp_image_undo_push_undo (gimage, undo);
+  if (gimp_image_undo_push_undo (gimage, undo))
+    return undo;
 
-  return undo;
+  return NULL;
 }
 
-void
+gboolean
 gimp_image_undo_push_undo (GimpImage *gimage,
                            GimpUndo  *undo)
 {
-  g_return_if_fail (GIMP_IS_IMAGE (gimage));
-  g_return_if_fail (GIMP_IS_UNDO (undo));
-  g_return_if_fail (undo->gimage == gimage);
-  g_return_if_fail (gimage->undo_freeze_count == 0);
+  g_return_val_if_fail (GIMP_IS_IMAGE (gimage), FALSE);
+  g_return_val_if_fail (GIMP_IS_UNDO (undo), FALSE);
+  g_return_val_if_fail (undo->gimage == gimage, FALSE);
+  g_return_val_if_fail (gimage->undo_freeze_count == 0, FALSE);
 
   /*  nuke the redo stack  */
   gimp_image_undo_free_redo (gimage);
@@ -275,9 +276,13 @@ gimp_image_undo_push_undo (GimpImage *gimage,
     {
       gimp_undo_stack_push_undo (gimage->undo_stack, undo);
 
+      gimp_image_undo_event (gimage, GIMP_UNDO_EVENT_UNDO_PUSHED, undo);
+
       gimp_image_undo_free_space (gimage);
 
-      gimp_image_undo_event (gimage, GIMP_UNDO_EVENT_UNDO_PUSHED, undo);
+      /*  freeing undo space may have freed the newly pushed undo  */
+      if (gimp_undo_stack_peek (gimage->undo_stack) == undo)
+        return TRUE;
     }
   else
     {
@@ -286,7 +291,11 @@ gimp_image_undo_push_undo (GimpImage *gimage,
       undo_group = GIMP_UNDO_STACK (gimp_undo_stack_peek (gimage->undo_stack));
 
       gimp_undo_stack_push_undo (undo_group, undo);
+
+      return TRUE;
     }
+
+  return FALSE;
 }
 
 

app/core/gimpimage-undo.h

@@ -47,7 +47,7 @@ GimpUndo * gimp_image_undo_push_item   (GimpImage        *gimage,
                                         gboolean          dirties_image,
                                         GimpUndoPopFunc   pop_func,
                                         GimpUndoFreeFunc  free_func);
-void       gimp_image_undo_push_undo   (GimpImage        *gimage,
+gboolean   gimp_image_undo_push_undo   (GimpImage        *gimage,
                                         GimpUndo         *undo);