Bug 1453668 - Restrict the retained display list stacking context optimization to frames that are also containing blocks for position:fixed. r?miko
MozReview-Commit-ID: GP4uMpR2Lq0
--- a/layout/painting/RetainedDisplayListBuilder.cpp
+++ b/layout/painting/RetainedDisplayListBuilder.cpp
@@ -742,17 +742,18 @@ ProcessFrame(nsIFrame* aFrame, nsDisplay
aOverflow.IntersectRect(aOverflow, currentFrame->GetVisualOverflowRectRelativeToSelf());
}
if (aOverflow.IsEmpty()) {
break;
}
if (currentFrame != aBuilder.RootReferenceFrame() &&
- currentFrame->IsStackingContext()) {
+ currentFrame->IsStackingContext() &&
+ currentFrame->IsFixedPosContainingBlock()) {
CRR_LOG("Frame belongs to stacking context frame %p\n", currentFrame);
// If we found an intermediate stacking context with an existing display item
// then we can store the dirty rect there and stop. If we couldn't find one then
// we need to keep bubbling up to the next stacking context.
nsDisplayItem* wrapperItem = GetFirstDisplayItemWithChildren(currentFrame);
if (!wrapperItem) {
continue;
}
--- a/layout/reftests/display-list/retained-dl-style-change-stacking-context-1.html
+++ b/layout/reftests/display-list/retained-dl-style-change-stacking-context-1.html
@@ -12,22 +12,18 @@
}
</style>
</head>
<body>
<div id="first" style="background-color:green; width:200px; height:200px" class="reftest-no-display-list"></div>
<div style="transform:translateZ(1px)">
<div id="second" style="background-color:red"></div>
</div>
- <div style="position:fixed; left:100px">
- <div id="third" style="background-color:red"></div>
- </div>
</body>
<script>
function doTest() {
document.getElementById("second").style.backgroundColor = "green";
- document.getElementById("third").style.backgroundColor = "green";
document.documentElement.removeAttribute("class");
}
window.addEventListener("MozReftestInvalidate", doTest);
</script>
</html>