[Cogl] [PATCH] Fix a clear of an array allocated with alloca which had the wrong size

[Neil Roberts]

The array allocated for storing the difference flags for each layer in
cogl-pipeline-opengl.c was being cleared with the size of a pointer
instead of the size actually allocated for the array. Presumably this
would mean that if there is more than one layer it wouldn't clear the
array properly.

Also the size of the array was slightly wrong because it was allocating
the size of a pointer for each layer instead of the size of an
unsigned long.

This was originally reported by Jasper St. Pierre on #clutter.
---
 cogl/driver/gl/cogl-pipeline-opengl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cogl/driver/gl/cogl-pipeline-opengl.c b/cogl/driver/gl/cogl-pipeline-opengl.c
index 0a7b4db..e4d2976 100644
--- a/cogl/driver/gl/cogl-pipeline-opengl.c
+++ b/cogl/driver/gl/cogl-pipeline-opengl.c
@@ -1173,8 +1173,8 @@ _cogl_pipeline_flush_gl_state (CoglPipeline *pipeline,
   if (n_layers)
     {
       CoglPipelineCompareLayersState state;
-      layer_differences = g_alloca (sizeof (unsigned long *) * n_layers);
-      memset (layer_differences, 0, sizeof (layer_differences));
+      layer_differences = g_alloca (sizeof (unsigned long) * n_layers);
+      memset (layer_differences, 0, sizeof (unsigned long) * n_layers);
       state.i = 0;
       state.layer_differences = layer_differences;
       _cogl_pipeline_foreach_layer_internal (pipeline,
-- 
1.7.11.3.g3c3efa5