Make g_tree_remove() and g_tree_steal() return FALSE if the node is found but cannot...

This should help people from freeing things accidentally based on the return result.  Also, change comments for these functions to reflect their behaviour in a tree with multiple versions.

diff --git a/glib/gtree.c b/glib/gtree.c
index 77ee5fc62535afb45e5a7dfb83939c86da35ec4e..6dde6ccbae8e8a8f79baae07a47d96b981225e18 100644 (file)
--- a/glib/gtree.c
+++ b/glib/gtree.c
@@ -804,10 +804,13 @@ g_tree_insert_internal (GTree    *tree,
  * If the #GTree was created using g_tree_new_full(), the key and value 
  * are freed using the supplied destroy functions, otherwise you have to 
  * make sure that any dynamically allocated values are freed yourself.
+ * Note that if the key existed in
+ * earlier versions of the tree (g_tree_next_version() has been called since
+ * it was inserted), then it cannot be removed from the tree. *
  * If the key does not exist in the #GTree, the function does nothing.
  *
- * Returns: %TRUE if the key was found (prior to 2.8, this function returned 
- *   nothing)
+ * Returns: %TRUE if the key was found and able to be removed
+ *   (prior to 2.8, this function returned nothing)
  **/
 gboolean
 g_tree_remove (GTree         *tree,
@@ -832,12 +835,13 @@ g_tree_remove (GTree         *tree,
  * @key: the key to remove.
  * 
  * Removes a key and its associated value from a #GTree without calling 
- * the key and value destroy functions.
- *
+ * the key and value destroy functions.  Note that if the key existed in
+ * earlier versions of the tree (g_tree_next_version() has been called since
+ * it was inserted), then it cannot be removed from the tree. *
  * If the key does not exist in the #GTree, the function does nothing.
  *
- * Returns: %TRUE if the key was found (prior to 2.8, this function returned 
- *    nothing)
+ * Returns: %TRUE if the key was found and able to be removed
+ *   (prior to 2.8, this function returned nothing)
  **/
 gboolean
 g_tree_steal (GTree         *tree,
@@ -976,6 +980,8 @@ g_tree_remove_internal (GTree         *tree,
         }
     }
 
+  tree->nnodes--;
+
   /* only really delete the node if it's in the current version, otherwise
      it needs to be remembered */
   if (node->nv == 1 && node->version(NOW) == tree->version)
@@ -993,11 +999,11 @@ g_tree_remove_internal (GTree         *tree,
                      (node->version(NOW) == 0 ? 1 : MAX_IN_DEGREE + 1),
                      node->v);
       g_slice_free (GTreeNode, node);
-    }
 
-  tree->nnodes--;
+      return TRUE;
+    }
 
-  return TRUE;
+  return FALSE;
 }
 
 /**