polygon-intersect: add missing null checkscarlosgc/polygon-intersect-crash

Return early if right becomes NULL.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/cairo-polygon-intersect.c b/src/cairo-polygon-intersect.c
index 001e55ee0..10d05e732 100644
--- a/src/cairo-polygon-intersect.c
+++ b/src/cairo-polygon-intersect.c
@@ -1167,6 +1167,9 @@ active_edges (cairo_bo_edge_t		*left,
 	    } while (1);
 
 	    right = left->next;
+            if (! right)
+                return;
+
 	    do {
 		if unlikely ((right->deferred.other))
 		    edges_end (right, top, polygon);
@@ -1179,6 +1182,8 @@ active_edges (cairo_bo_edge_t		*left,
 		}
 
 		right = right->next;
+                if (! right)
+                    return;
 	    } while (1);
 
 	    edges_start_or_continue (left, right, top, polygon);