[dia] grid-object: avoid crash on shrink

[Hans Breuer <hans src gnome org>]

commit cddd958b71a4075751ab76ac3530ced3c33972ea
Author: Hans Breuer <hans breuer org>
Date:   Thu Oct 7 13:21:16 2010 +0200

    grid-object: avoid crash on shrink
    
    Fix some confusion about rows/columns using the wrong limits.
    Resizing object::connections was too early.

 objects/Misc/grid_object.c |   15 ++++++++-------
 1 files changed, 8 insertions(+), 7 deletions(-)
---
diff --git a/objects/Misc/grid_object.c b/objects/Misc/grid_object.c
index b6dcf9c..e34e63f 100644
--- a/objects/Misc/grid_object.c
+++ b/objects/Misc/grid_object.c
@@ -459,12 +459,6 @@ grid_object_reallocate_cells (Grid_Object* grid_object)
   if (old_rows == new_rows && old_cols == new_cols)
     return;  /* no reallocation necessary */
 
-  /* obj->connections doesn't own the pointers, so just realloc; values
-   * will be updated later */
-  obj->num_connections = GRID_OBJECT_BASE_CONNECTION_POINTS + new_rows*new_cols;
-  obj->connections = (ConnectionPoint **) g_realloc(obj->connections,
-      		obj->num_connections * sizeof(ConnectionPoint *));
-
   /* If either new dimension is smaller, some connpoints will have to
    * be disconnected before reallocating */
 
@@ -478,12 +472,19 @@ grid_object_reallocate_cells (Grid_Object* grid_object)
 
   /* implicit: if (new_cols < old_cols) */
   for (i = new_cols; i < old_cols; ++i)
-    for (j = 0; j < old_cols && j < new_cols; ++j) /* don't double-delete */
+    for (j = 0; j < old_rows && j < new_rows; ++j) /* don't double-delete */
     {
       int cell = grid_cell(i, j, old_rows, old_cols);
       object_remove_connections_to(&grid_object->cells[cell]);
     }
 
+  /* must be done after disconnecting */
+  /* obj->connections doesn't own the pointers, so just realloc; values
+   * will be updated later */
+  obj->num_connections = GRID_OBJECT_BASE_CONNECTION_POINTS + new_rows*new_cols;
+  obj->connections = (ConnectionPoint **) g_realloc(obj->connections,
+      		obj->num_connections * sizeof(ConnectionPoint *));
+
   /* Can't use realloc; if grid has different dims, memory lays out
    * differently.  Must copy by hand. */