Better handling of event removal. This allows us to actually

clean up, but also makes sure we don't destroy the handler
list out from under us as we're processing events.



git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@13196 57a11ea4-9604-0410-9ed3-97b8803252fd

ChangeLog

@@ -11,6 +11,11 @@
 	  detects that we're running on a "broken" system like Ubuntu.
 	  This is in response to #330539.
 
+	* lib/libqof/qof/gnc-event.c:
+	  Better handling of event removal.  This allows us to actually
+	  clean up, but also makes sure we don't destroy the handler
+	  list out from under us as we're processing events.
+
 2006-02-09  David Hampton  <hampton@employees.org>
 
 	* src/bin/gnucash-bin.c: Pass argc by reference instead of value

lib/libqof/qof/gnc-event.c

@@ -38,6 +38,8 @@ typedef struct
 /* Static Variables ************************************************/
 static guint  suspend_counter = 0;
 static gint   next_handler_id = 1;
+static guint  handler_run_level = 0;
+static guint  pending_deletes = 0;
 static GList *handlers = NULL;
 
 /* This static indicates the debugging module that this .o belongs to.  */
@@ -113,14 +115,20 @@ gnc_engine_unregister_event_handler (gint handler_id)
        of a generated event, such as GNC_EVENT_DESTROY.  In that case,
        we're in the middle of walking the GList and it is wrong to
        modify the list. So, instead, we just NULL the handler. */ 
-    /* handlers = g_list_remove_link (handlers, node); */
 
-    LEAVE ("(handler_id=%d) handler=%p data=%p", handler_id, hi->handler, hi->user_data);
-    /* safety */
+    LEAVE ("(handler_id=%d) handler=%p data=%p", handler_id,
+	   hi->handler, hi->user_data);
+
+    /* safety -- clear the handler in case we're running events now */
     hi->handler = NULL;
 
-    /* g_list_free_1 (node);
-       g_free (hi); */
+    if (handler_run_level == 0) {
+      handlers = g_list_remove_link (handlers, node);
+      g_list_free_1 (node);
+      g_free (hi);
+    } else {
+      pending_deletes++;
+    }
 
     return;
   }
@@ -177,6 +185,7 @@ gnc_engine_generate_event_internal (QofEntity *entity,
       return;
   }
 
+  handler_run_level++;
   for (node = handlers; node; node = next_node)
   {
     HandlerInfo *hi = node->data;
@@ -184,7 +193,29 @@ gnc_engine_generate_event_internal (QofEntity *entity,
     next_node = node->next;
     PINFO ("id=%d hi=%p han=%p", hi->handler_id, hi, hi->handler);
     if (hi->handler)
-      hi->handler ((GUID *)&entity->guid, entity->e_type, event_type, hi->user_data);
+      hi->handler ((GUID *)&entity->guid, entity->e_type,
+		   event_type, hi->user_data);
+  }
+  handler_run_level--;
+
+  /* If we're the outtermost event runner and we have pending deletes
+   * then go delete the handlers now.
+   */
+  if (handler_run_level == 0 && pending_deletes)
+  {
+    for (node = handlers; node; node = next_node)
+    {
+      HandlerInfo *hi = node->data;
+      next_node = node->next;
+      if (hi->handler == NULL)
+      {
+	/* remove this node from the list, then free this node */
+	handlers = g_list_remove_link (handlers, node);
+	g_list_free_1 (node);
+	g_free (hi);
+      }
+    }
+    pending_deletes = 0;
   }
 }