[gimp/gimp-2-8] Bug 688746 - Select tool Alt+Shift and Alt+Ctrl dragging modifies...

[Michael Natterer <mitch src gnome org>]

commit 205c64d1b8ee9482a5c4eee9ff71c3ab53831805
Author: Michael Natterer <mitch gimp org>
Date:   Fri Dec 14 23:02:56 2012 +0100

    Bug 688746 - Select tool Alt+Shift and Alt+Ctrl dragging modifies...
    
    Check for layer groups and locked layers in gimp_selection_tool_start_edit()
    and show the usual warning instead of allowing the forbidden operation.
    (cherry picked from commit 593ddb741f1479fddf25d708ae8d4411b9408f28)

 app/tools/gimpselectiontool.c |   37 +++++++++++++++++++++++++++++--------
 1 files changed, 29 insertions(+), 8 deletions(-)
---
diff --git a/app/tools/gimpselectiontool.c b/app/tools/gimpselectiontool.c
index 438d733..d3111e0 100644
--- a/app/tools/gimpselectiontool.c
+++ b/app/tools/gimpselectiontool.c
@@ -416,15 +416,36 @@ gimp_selection_tool_start_edit (GimpSelectionTool *sel_tool,
       return TRUE;
 
     case SELECTION_MOVE:
-      gimp_edit_selection_tool_start (tool, display, coords,
-                                      GIMP_TRANSLATE_MODE_MASK_TO_LAYER, FALSE);
-      return TRUE;
-
     case SELECTION_MOVE_COPY:
-      gimp_edit_selection_tool_start (tool, display, coords,
-                                      GIMP_TRANSLATE_MODE_MASK_COPY_TO_LAYER,
-                                      FALSE);
-      return TRUE;
+      {
+        GimpImage    *image    = gimp_display_get_image (display);
+        GimpDrawable *drawable = gimp_image_get_active_drawable (image);
+
+        if (gimp_viewable_get_children (GIMP_VIEWABLE (drawable)))
+          {
+            gimp_tool_message_literal (tool, display,
+                                       _("Cannot modify the pixels of layer groups."));
+          }
+        else if (gimp_item_is_content_locked (GIMP_ITEM (drawable)))
+          {
+            gimp_tool_message_literal (tool, display,
+                                       _("The active layer's pixels are locked."));
+          }
+        else
+          {
+            GimpTranslateMode edit_mode;
+
+            if (sel_tool->function == SELECTION_MOVE)
+              edit_mode = GIMP_TRANSLATE_MODE_MASK_TO_LAYER;
+            else
+              edit_mode = GIMP_TRANSLATE_MODE_MASK_COPY_TO_LAYER;
+
+            gimp_edit_selection_tool_start (tool, display, coords,
+                                            edit_mode, FALSE);
+         }
+
+        return TRUE;
+      }
 
     default:
       break;