[librsvg] feTile: don't divide by zero if the input surface has empty bounds

[Federico Mena Quintero <federico src gnome org>]

commit 6a94a7aa4f722bd08f7b677900d0329309ed029f
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Jul 6 13:02:03 2017 -0500

    feTile: don't divide by zero if the input surface has empty bounds
    
    Thanks to Stefan Cornelius <scorneli redhat com> for the test file.

 rsvg-filter.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/rsvg-filter.c b/rsvg-filter.c
index 804d637..bd6c8f2 100644
--- a/rsvg-filter.c
+++ b/rsvg-filter.c
@@ -4947,6 +4947,11 @@ rsvg_filter_primitive_tile_render (RsvgNode *node, RsvgFilterPrimitive *primitiv
     in = input.surface;
     boundarys = input.bounds;
 
+    if ((boundarys.x0 >= boundarys.x1) || (boundarys.y0 >= boundarys.y1)) {
+        cairo_surface_destroy (in);
+        return;
+    }
+
     cairo_surface_flush (in);
 
     in_pixels = cairo_image_surface_get_data (in);