[librsvg] rsvg-filter: Deal with errors in all callers to rsvg_filter_get_result()

[Federico Mena Quintero <federico src gnome org>]

commit 762d570ac599a001b6ba23110fc0789546f48770
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Jul 7 11:42:35 2017 -0500

    rsvg-filter: Deal with errors in all callers to rsvg_filter_get_result()

 rsvg-filter.c |   15 ++++++++-------
 1 files changed, 8 insertions(+), 7 deletions(-)
---
diff --git a/rsvg-filter.c b/rsvg-filter.c
index ff7172c..e6e41d6 100644
--- a/rsvg-filter.c
+++ b/rsvg-filter.c
@@ -1963,17 +1963,14 @@ rsvg_filter_primitive_gaussian_blur_render (RsvgNode *node, RsvgFilterPrimitive
 
     boundarys = rsvg_filter_primitive_get_bounds (primitive, ctx);
 
-    op = rsvg_filter_get_result (primitive->in, ctx);
-    in = op.surface;
+    in = rsvg_filter_get_in (primitive->in, ctx);
+    if (in == NULL) {
+        return;
+    }
 
     width = cairo_image_surface_get_width (in);
     height = cairo_image_surface_get_height (in);
 
-    if (width == 0 || height == 0) {
-        cairo_surface_destroy (in);
-        return;
-    }
-
     output = _rsvg_image_surface_new (width, height);
 
     if (output == NULL) {
@@ -4946,6 +4943,10 @@ rsvg_filter_primitive_tile_render (RsvgNode *node, RsvgFilterPrimitive *primitiv
 
     input = rsvg_filter_get_result (primitive->in, ctx);
     in = input.surface;
+    if (in == NULL) {
+        return;
+    }
+
     boundarys = input.bounds;
 
     if ((boundarys.x0 >= boundarys.x1) || (boundarys.y0 >= boundarys.y1)) {