[gimp] app: update image menu when starting a blend-tool edit action

[N/A <ell src gnome org>]

commit 6a6af19ff846ed612c325a95f75d112dedd3ff73
Author: Ell <ell_se yahoo com>
Date:   Thu Nov 16 11:03:00 2017 -0500

    app: update image menu when starting a blend-tool edit action
    
    ... since we can't undo blend steps while an action is in progress.

 app/tools/gimpblendtool-editor.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/app/tools/gimpblendtool-editor.c b/app/tools/gimpblendtool-editor.c
index ce70dde..4a2fb8f 100644
--- a/app/tools/gimpblendtool-editor.c
+++ b/app/tools/gimpblendtool-editor.c
@@ -2383,6 +2383,14 @@ gimp_blend_tool_editor_start_edit (GimpBlendTool *blend_tool)
       info = gimp_blend_tool_editor_blend_info_new (blend_tool);
 
       blend_tool->undo_stack = g_slist_prepend (blend_tool->undo_stack, info);
+
+      /*  update the undo actions / menu items  */
+      if (! blend_tool->flush_idle_id)
+        {
+          blend_tool->flush_idle_id =
+            g_idle_add ((GSourceFunc) gimp_blend_tool_editor_flush_idle,
+                        blend_tool);
+        }
     }
 }