[gnome-builder] source-view: handle shift-tab same as GDK_KEY_ISO_Left_Tab

[Christian Hergert <chergert src gnome org>]

commit 9eba53125b65a1ce085b69b35ff8c17d4e6c9f3d
Author: Christian Hergert <chergert redhat com>
Date:   Wed Nov 9 20:00:35 2016 -0800

    source-view: handle shift-tab same as GDK_KEY_ISO_Left_Tab

 libide/sourceview/ide-source-view.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)
---
diff --git a/libide/sourceview/ide-source-view.c b/libide/sourceview/ide-source-view.c
index 6649b6f..2724b80 100644
--- a/libide/sourceview/ide-source-view.c
+++ b/libide/sourceview/ide-source-view.c
@@ -2371,13 +2371,16 @@ ide_source_view_key_press_event (GtkWidget   *widget,
 
         case GDK_KEY_KP_Tab:
         case GDK_KEY_Tab:
-          ide_source_view_block_handlers (self);
-          if (!ide_source_snippet_move_next (snippet))
-            ide_source_view_pop_snippet (self);
-          ide_source_view_scroll_to_insert (self);
-          ide_source_view_unblock_handlers (self);
-          return TRUE;
-
+          if ((event->state & GDK_SHIFT_MASK) == 0)
+            {
+              ide_source_view_block_handlers (self);
+              if (!ide_source_snippet_move_next (snippet))
+                ide_source_view_pop_snippet (self);
+              ide_source_view_scroll_to_insert (self);
+              ide_source_view_unblock_handlers (self);
+              return TRUE;
+            }
+          /* Fallthrough */
         case GDK_KEY_ISO_Left_Tab:
           ide_source_view_block_handlers (self);
           ide_source_snippet_move_previous (snippet);