Update internal state on undo to avoid a crash.

third_party/undoview/undo_manager.c

 /*
  * Copyright (C) 1998, 1999 Alex Roberts, Evan Lawrence
  * Copyright (C) 2000, 2001 Chema Celorio, Paolo Maggi
  * Copyright (C) 2002-2005 Paolo Maggi
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
@@ skipping 100 matching lines @@
    * from the action list (freeing the list or resizing it) */
   GtkSourceUndoAction *modified_action;
 };
 
 enum {
   CAN_UNDO,
   CAN_REDO,
   LAST_SIGNAL
 };
 
+#if !defined(NDEBUG)
+static void
+print_state(GtkSourceUndoManager* um)
+{
+  fprintf(stderr, "\n***\n");
+  GList* actions = um->priv->actions;
+
+  for (; actions; actions = g_list_next(actions)) {
+    GtkSourceUndoAction* act = actions->data;
+    fprintf(stderr, "* type = %s\n", act->action_type == GTK_SOURCE_UNDO_ACTION_DELETE ?
+        "delete" : "insert");
+
+    fprintf(stderr, "\ttext = %s\n", act->action_type == GTK_SOURCE_UNDO_ACTION_DELETE
+        ? act->action.delete.text : act->action.insert.text);
+    fprintf(stderr, "\torder = %d\n", act->order_in_group);
+  }
+
+  fprintf(stderr, "* next redo: %d\n", um->priv->next_redo);
+  fprintf(stderr, "* num of groups: %d\n", um->priv->num_of_groups);
+  fprintf(stderr, "* actions in group: %d\n", um->priv->actions_in_current_group);
+}
+#endif
+
 static void gtk_source_undo_manager_class_init(GtkSourceUndoManagerClass *klass);
 static void gtk_source_undo_manager_init(GtkSourceUndoManager *um);
 static void gtk_source_undo_manager_finalize(GObject *object);
 
 static void gtk_source_undo_manager_insert_text_handler(GtkTextBuffer *buffer,
                   GtkTextIter *pos,
                                          const gchar *text,
                   gint length,
                   GtkSourceUndoManager *um);
 static void gtk_source_undo_manager_delete_range_handler(GtkTextBuffer *buffer,
@@ skipping 486 matching lines @@
   GList *l;
 
   l = um->priv->actions;
 
   while(l != NULL)
   {
     GtkSourceUndoAction *action = l->data;
 
     if(action->order_in_group == 1)
       --um->priv->num_of_groups;
+    um->priv->actions_in_current_group = action->order_in_group - 1;
 
     if(action->modified)
       um->priv->modified_action = INVALID;
 
     gtk_source_undo_action_free(action);
 
     l = g_list_next(l);
   }
 
   g_list_free(um->priv->actions);
@@ skipping 143 matching lines @@
 
   if(um->priv->actions == NULL)
     return;
 
   for(i = 0; i < n; i++)
   {
     GtkSourceUndoAction *action = g_list_first(um->priv->actions)->data;
 
     if(action->order_in_group == 1)
       --um->priv->num_of_groups;
+    um->priv->actions_in_current_group = action->order_in_group - 1;
 
     if(action->modified)
       um->priv->modified_action = INVALID;
 
     gtk_source_undo_action_free(action);
 
     um->priv->actions = g_list_delete_link(um->priv->actions,
               um->priv->actions);
 
     if(um->priv->actions == NULL)
@@ skipping 20 matching lines @@
 
     last = g_list_last(um->priv->actions);
     undo_action =(GtkSourceUndoAction*) last->data;
 
     do
     {
       GList *tmp;
 
       if(undo_action->order_in_group == 1)
         --um->priv->num_of_groups;
+      um->priv->actions_in_current_group = undo_action->order_in_group - 1;
 
       if(undo_action->modified)
         um->priv->modified_action = INVALID;
 
       gtk_source_undo_action_free(undo_action);
 
       tmp = g_list_previous(last);
       um->priv->actions = g_list_delete_link(um->priv->actions, last);
       last = tmp;
       g_return_if_fail(last != NULL);
@@ skipping 235 matching lines @@
     g_return_if_fail(list != NULL);
 
     action =(GtkSourceUndoAction*) list->data;
     g_return_if_fail(action != NULL);
   }
 
   action->modified = TRUE;
   um->priv->modified_action = action;
 }