[librsvg] Fix refcount problem

[Christian Persch <chpe src gnome org>]

commit 167533f0b308b6f4f5799b7ad3a29d40c8d9fc1a
Author: Christian Persch <chpe gnome org>
Date:   Tue Nov 29 00:05:36 2011 +0100

    Fix refcount problem
    
    Need to reference the source surface put into the results stack. This fixes
    a regression introduced in commit 1b3d2ea55a1be67e0548bf76903ff905888e2e18.

 rsvg-filter.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/rsvg-filter.c b/rsvg-filter.c
index a181943..7d4aada 100644
--- a/rsvg-filter.c
+++ b/rsvg-filter.c
@@ -513,7 +513,7 @@ rsvg_filter_render (RsvgFilter *self,
 
     rsvg_filter_fix_coordinate_system (ctx, rsvg_current_state (context), bounds);
 
-    ctx->lastresult.surface = source;
+    ctx->lastresult.surface = cairo_surface_reference (source);
     ctx->lastresult.Rused = 1;
     ctx->lastresult.Gused = 1;
     ctx->lastresult.Bused = 1;