[gimp] Bug 790810 - Nested layer groups lead to a deadlock with multithreading

[N/A <ell src gnome org>]

commit 2ff52af5a9e8ea621068c560fd3c1ca9e1a61dff
Author: Ell <ell_se yahoo com>
Date:   Sun Nov 26 10:45:33 2017 -0500

    Bug 790810 - Nested layer groups lead to a deadlock with multithreading
    
    Temporarily disable multithreading for GimpOperationLayerMode, to
    avoid the deadlock.  The environment variable
    GIMP_MULTITHREADED_COMPOSITING can be set to reenable it, for the
    sake of debugging.

 .../layer-modes/gimpoperationlayermode.c           |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/app/operations/layer-modes/gimpoperationlayermode.c 
b/app/operations/layer-modes/gimpoperationlayermode.c
index f2998ff..5309460 100644
--- a/app/operations/layer-modes/gimpoperationlayermode.c
+++ b/app/operations/layer-modes/gimpoperationlayermode.c
@@ -152,6 +152,10 @@ gimp_operation_layer_mode_class_init (GimpOperationLayerModeClass *klass)
   klass->process                 = gimp_operation_layer_mode_real_process;
   klass->get_affected_region     = NULL;
 
+  /* XXX: temporarily disable multithreaded compositing.  see bug #790810.  */
+  if (! g_getenv ("GIMP_MULTITHREADED_COMPOSITING"))
+    operation_class->threaded = FALSE;
+
   g_object_class_install_property (object_class, PROP_LAYER_MODE,
                                    g_param_spec_enum ("layer-mode",
                                                       NULL, NULL,