Bugfix #26424

More problems with Undo and Render Slots (Image editor)

- Undo storage for operator is now back, but only when new
  buffers were added (not when viewing existing)

- A real bug: On undo/redo, the stored buffers were never
  retrieved, but always freed entirely.

Note however that when you undo back to a state before you
rendered (or added slots), the render buffers that didn't
exist back then also get freed. A redo doesn't bring it back.

1 files changed, 6 insertions, 1 deletions

diff --git a/source/blender/editors/space_image/image_ops.c b/source/blender/editors/space_image/image_ops.c
index 34b0bffde8e..3990f0916b1 100644
--- a/source/blender/editors/space_image/image_ops.c
+++ b/source/blender/editors/space_image/image_ops.c
@@ -2133,6 +2133,10 @@ static int cycle_render_slot_exec(bContext *C, wmOperator *op)
 	
 	WM_event_add_notifier(C, NC_IMAGE|ND_DRAW, NULL);
 
+	/* no undo push for browsing existing */
+	if(ima->renders[ima->render_slot])
+		return OPERATOR_CANCELLED;
+	
 	return OPERATOR_FINISHED;
 }
 
@@ -2146,7 +2150,8 @@ void IMAGE_OT_cycle_render_slot(wmOperatorType *ot)
 	ot->exec= cycle_render_slot_exec;
 	ot->poll= cycle_render_slot_poll;
 
-	/* no registry or undo flags, this is a UI option */
+	/* flags */
+	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
 
 	RNA_def_boolean(ot->srna, "reverse", 0, "Cycle in Reverse", "");
 }