[Cogl] [PATCH 2/2] error: Don't allocate a new CoglError when propagating

[Neil Roberts]

The _cogl_propagate_error() function takes ownership of the incoming
error pointer so there's no need to allocate a new error when passing
it on. The errors can potentially be passed up from a number of layers
so it seems worthwhile to avoid the allocation.

The _cogl_propagate_gerror() function was previously using
_cogl_propagate_error(). Presumably this would not have worked because
that function would try to free the error from glib using
cogl_error_free but that would use the wrong free function and thus
the wrong slice allocator. The GError propagating function is only
used when gdk-pixbuf is enabled which now requires glib support anyway
so we can just avoid defining the function when compiling without
glib.
---
 cogl/cogl-error-private.h |  2 ++
 cogl/cogl-error.c         | 17 ++++++++++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/cogl/cogl-error-private.h b/cogl/cogl-error-private.h
index 31b2eab..a886084 100644
--- a/cogl/cogl-error-private.h
+++ b/cogl/cogl-error-private.h
@@ -43,9 +43,11 @@ void
 _cogl_propagate_error (CoglError **dest,
                        CoglError *src);
 
+#ifdef COGL_HAS_GLIB_SUPPORT
 void
 _cogl_propagate_gerror (CoglError **dest,
                         GError *src);
+#endif /* COGL_HAS_GLIB_SUPPORT */
 
 #define _cogl_clear_error(X) g_clear_error ((GError **)X)
 
diff --git a/cogl/cogl-error.c b/cogl/cogl-error.c
index 4ef3681..753e4c8 100644
--- a/cogl/cogl-error.c
+++ b/cogl/cogl-error.c
@@ -104,13 +104,24 @@ _cogl_propagate_error (CoglError **dest,
 {
   _COGL_RETURN_IF_FAIL (src != NULL);
 
-  _cogl_set_error_literal (dest, src->domain, src->code, src->message);
-  cogl_error_free (src);
+  if (dest == NULL)
+    cogl_error_free (src);
+  else if (*dest)
+    g_warning (ERROR_OVERWRITTEN_WARNING, src->message);
+  else
+    *dest = src;
 }
 
+/* This function is only used from the gdk-pixbuf image backend so it
+ * should only be called if we are using the system GLib. It would be
+ * difficult to get this to work without the system glib because we
+ * would need to somehow call the same g_error_free function that
+ * gdk-pixbuf is using */
+#ifdef COGL_HAS_GLIB_SUPPORT
 void
 _cogl_propagate_gerror (CoglError **dest,
                         GError *src)
 {
-  _cogl_propagate_error (dest, (CoglError *)src);
+  _cogl_propagate_error (dest, (CoglError *) src);
 }
+#endif /* COGL_HAS_GLIB_SUPPORT */
-- 
1.7.11.3.g3c3efa5