[gegl/gsoc2009-gpu] Fix segmentation fault caused by NULL accesses to GeglBufferIterator's internal buffer pools

[Jerson Michael Perpetua <jperpetua src gnome org>]

commit 6cb6d653885e4ab291f03c7f34fd03432220ce4c
Author: Jerson Michael Perpetua <jersonperpetua gmail com>
Date:   Mon Jul 13 13:58:14 2009 +0800

    Fix segmentation fault caused by NULL accesses to GeglBufferIterator's internal buffer pools

 gegl/buffer/gegl-buffer-iterator.c |   38 ++++++++++++++++++++---------------
 1 files changed, 22 insertions(+), 16 deletions(-)
---
diff --git a/gegl/buffer/gegl-buffer-iterator.c b/gegl/buffer/gegl-buffer-iterator.c
index a393be7..c1cede2 100644
--- a/gegl/buffer/gegl-buffer-iterator.c
+++ b/gegl/buffer/gegl-buffer-iterator.c
@@ -467,28 +467,34 @@ gegl_buffer_iterator_cleanup (void)
 {
   gint cnt;
 
-  for (cnt = 0; cnt < buf_pool->len; cnt++)
+  if (buf_pool != NULL)
     {
-      BufInfo *info = &g_array_index (buf_pool, BufInfo, cnt);
-      gegl_free (info->buf);
-      info->buf = NULL;
-    }
+      for (cnt = 0; cnt < buf_pool->len; cnt++)
+        {
+          BufInfo *info = &g_array_index (buf_pool, BufInfo, cnt);
+          gegl_free (info->buf);
+          info->buf = NULL;
+        }
 
-  g_array_free (buf_pool, TRUE);
-  buf_pool = NULL;
+      g_array_free (buf_pool, TRUE);
+      buf_pool = NULL;
+    }
 
-  for (cnt = 0; cnt < gpu_texture_pool->len; cnt++)
+  if (gpu_texture_pool != NULL)
     {
-      GpuTextureInfo *info = &g_array_index (gpu_texture_pool,
-                                             GpuTextureInfo,
-                                             cnt);
+      for (cnt = 0; cnt < gpu_texture_pool->len; cnt++)
+        {
+          GpuTextureInfo *info = &g_array_index (gpu_texture_pool,
+                                                 GpuTextureInfo,
+                                                 cnt);
 
-      gegl_gpu_texture_free (info->texture);
-      info->texture = NULL;
-    }
+          gegl_gpu_texture_free (info->texture);
+          info->texture = NULL;
+        }
 
-  g_array_free (gpu_texture_pool, TRUE);
-  gpu_texture_pool = NULL;
+      g_array_free (gpu_texture_pool, TRUE);
+      gpu_texture_pool = NULL;
+    }
 }
 
 #if DEBUG_DIRECT