[gimp/wip/animation: 70/145] plug-ins: handling deleted layers.

[Jehan Pagès <jehanp src gnome org>]

commit b0cad41c03b394151c03226312f983800bf7f82f
Author: Jehan <jehan girinstud io>
Date:   Wed Nov 16 04:34:41 2016 +0100

    plug-ins: handling deleted layers.
    
    WIP: maybe I should just gray it or something? Allowing to hit "Undo"?

 .../animation-play/core/animation-celanimation.c   |    9 ++++++++-
 plug-ins/animation-play/widgets/animation-xsheet.c |   20 ++++++++++++++++++--
 2 files changed, 26 insertions(+), 3 deletions(-)
---
diff --git a/plug-ins/animation-play/core/animation-celanimation.c 
b/plug-ins/animation-play/core/animation-celanimation.c
index ee9156a..7bd4c54 100644
--- a/plug-ins/animation-play/core/animation-celanimation.c
+++ b/plug-ins/animation-play/core/animation-celanimation.c
@@ -1222,7 +1222,14 @@ animation_cel_animation_cache (AnimationCelAnimation *animation,
 
       layer = gimp_image_get_layer_by_tattoo (image_id,
                                               cache->composition[i]);
-      source = gimp_drawable_get_buffer (layer);
+      if (layer > 0)
+        source = gimp_drawable_get_buffer (layer);
+      if (layer <= 0 || ! source)
+        {
+          g_warning ("A layer used for frame %d has been removed. Ignoring.",
+                     pos);
+          continue;
+        }
       gimp_drawable_offsets (layer, &layer_offx, &layer_offy);
       intermediate = normal_blend (preview_width, preview_height,
                                    backdrop, 1.0, 0, 0,
diff --git a/plug-ins/animation-play/widgets/animation-xsheet.c 
b/plug-ins/animation-play/widgets/animation-xsheet.c
index 0616d50..ad88a42 100755
--- a/plug-ins/animation-play/widgets/animation-xsheet.c
+++ b/plug-ins/animation-play/widgets/animation-xsheet.c
@@ -1528,7 +1528,7 @@ animation_xsheet_rename_cel (AnimationXSheet *xsheet,
   else if (layers)
     {
       const gchar *track_title;
-      gchar       *layer_title;
+      gchar       *layer_title = NULL;
       gint32       image_id;
       gint32       layer;
 
@@ -1537,7 +1537,23 @@ animation_xsheet_rename_cel (AnimationXSheet *xsheet,
       image_id = animation_get_image_id (ANIMATION (xsheet->priv->animation));
       layer = gimp_image_get_layer_by_tattoo (image_id,
                                               GPOINTER_TO_INT (layers->data));
-      layer_title = gimp_item_get_name (layer);
+      if (layer <= 0)
+        {
+          g_warning ("Removing invalid layer from cell: level %d, frame %d.",
+                     GPOINTER_TO_INT (track_num),
+                     GPOINTER_TO_INT (position));
+          /* Update the layer list on this cell. */
+          animation_cel_animation_set_layers (xsheet->priv->animation,
+                                              GPOINTER_TO_INT (track_num),
+                                              GPOINTER_TO_INT (position),
+                                              NULL);
+          animation_xsheet_rename_cel (xsheet, cel, recursively);
+          return;
+        }
+      else
+        {
+          layer_title = gimp_item_get_name (layer);
+        }
       if (g_strcmp0 (layer_title, track_title) == 0)
         {
           /* If the track and the layer have exactly the same name. */