From 14879d50bcfe2f90dfceb96861b745c47ac7aaa9 Mon Sep 17 00:00:00 2001
From: Markus Stange <mstange@themasta.com>
Date: Tue, 10 Dec 2013 14:50:41 +0100
Subject: [PATCH] Bug 945655 - Composite filters with operator IN have a result
 that is the intersection of the input rects, not the union.
 FilterNodeSoftware part. r=roc

---
 gfx/2d/FilterNodeSoftware.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gfx/2d/FilterNodeSoftware.cpp b/gfx/2d/FilterNodeSoftware.cpp
index 1baa66fda80..840bd719c35 100644
--- a/gfx/2d/FilterNodeSoftware.cpp
+++ b/gfx/2d/FilterNodeSoftware.cpp
@@ -2652,7 +2652,12 @@ FilterNodeCompositeSoftware::GetOutputRectInRect(const IntRect& aRect)
 {
   IntRect rect;
   for (size_t inputIndex = 0; inputIndex < NumberOfSetInputs(); inputIndex++) {
-    rect = rect.Union(GetInputRectInRect(IN_COMPOSITE_IN_START + inputIndex, aRect));
+    IntRect inputRect = GetInputRectInRect(IN_COMPOSITE_IN_START + inputIndex, aRect);
+    if (mOperator == COMPOSITE_OPERATOR_IN && inputIndex > 0) {
+      rect = rect.Intersect(inputRect);
+    } else {
+      rect = rect.Union(inputRect);
+    }
   }
   return rect;
 }