[gegl/soc-2011-warp] gegl-processor: add a g_return_if_fail to prevent a segfault if a sink operator has no input

[Michael Murà <mmure src gnome org>]

commit b1e4c6bd0b939a1f39baf2ebb4f7638d820f0df3
Author: Michael Murà <batolettre gmail com>
Date:   Tue Aug 16 23:11:49 2011 +0200

    gegl-processor: add a g_return_if_fail to prevent a segfault if a sink operator has no input

 gegl/process/gegl-processor.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/gegl/process/gegl-processor.c b/gegl/process/gegl-processor.c
index 4bd9598..08c42a8 100644
--- a/gegl/process/gegl-processor.c
+++ b/gegl/process/gegl-processor.c
@@ -281,6 +281,8 @@ gegl_processor_set_node (GeglProcessor *processor,
       processor->valid_region = NULL;
     }
 
+  g_return_if_fail (processor->input);
+
   g_object_ref (processor->input);
 
   g_object_notify (G_OBJECT (processor), "node");