Bug 1381134 - Ensure we're using the correct frame for the :after/:before references

Tag #1375

layout/base/nsCSSFrameConstructor.cpp

@@ -6076,12 +6076,10 @@ nsCSSFrameConstructor::AddFrameConstructionItemsInternal(nsFrameConstructorState
 static void
 AddGenConPseudoToFrame(nsIFrame* aOwnerFrame, nsIContent* aContent)
 {
-  NS_ASSERTION(nsLayoutUtils::IsFirstContinuationOrIBSplitSibling(aOwnerFrame),
-               "property should only be set on first continuation/ib-sibling");
-
   // FIXME(emilio): Remove this property, and use the frame of the generated
   // content itself to tear the content down? It should be quite simpler.
 
+  aOwnerFrame = nsLayoutUtils::FirstContinuationOrIBSplitSibling(aOwnerFrame);
   nsIFrame::ContentArray* value =
     aOwnerFrame->GetProperty(nsIFrame::GenConProperty());
   if (!value) {
@@ -6343,7 +6341,9 @@ AdjustAppendParentForAfterContent(nsFrameManager* aFrameManager,
   // frames to find the first one that is either a ::after frame for an
   // ancestor of aChild or a frame that is for a node later in the
   // document than aChild and return that in aAfterFrame.
-  if (aParentFrame->GetProperty(nsIFrame::GenConProperty()) ||
+  nsIFrame* afterBeforeOwnerFrame =
+    nsLayoutUtils::FirstContinuationOrIBSplitSibling(aParentFrame);
+  if (afterBeforeOwnerFrame->GetProperty(nsIFrame::GenConProperty()) ||
       nsLayoutUtils::HasPseudoStyle(aContainer, aParentFrame->StyleContext(),
                                     CSSPseudoElementType::after,
                                     aParentFrame->PresContext()) ||

layout/generic/crashtests/1381134-2.html

@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="UTF-8">
+<script>
+addEventListener("DOMContentLoaded", () => {
+  [d1, d2] = document.getElementsByTagName("div");
+  [s1, s2] = document.getElementsByTagName("span")
+  d3 = document.createElement("div")
+  d4 = document.createElement("div")
+  d4.setAttribute("class", "grid")
+  d3.appendChild(d4)
+  d1.appendChild(document.createElement("span"))
+  setTimeout(() => {
+    d2.removeChild(s2)
+    setTimeout(() => {
+      d2.insertBefore(d3, s1)
+    }, 100)
+  }, 100)
+})
+</script>
+<style>
+.columns {
+  columns: 3;
+}
+.grid {
+  border:5px solid;
+  counter-reset: item;
+}
+.grid * { display:block; }
+span { display:contents; }
+span::before { content: counter(item) ":before"; }
+span::after { content: counter(item) ":after"; }
+</style>
+</head>
+<body>
+<div class=columns>
+<div class=grid>
+<c></c>
+<span><c></c></span>
+<span><c></c></span>
+</div>
+</div>
+</body>
+</html>

layout/generic/crashtests/1381134.html

@@ -0,0 +1,45 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="UTF-8">
+<script>
+addEventListener("DOMContentLoaded", () => {
+  [d1, d2] = document.getElementsByTagName("div");
+  [s1, s2] = document.getElementsByTagName("span")
+  d3 = document.createElement("div")
+  d4 = document.createElement("div")
+  d4.setAttribute("class", "grid")
+  d3.appendChild(d4)
+  d1.appendChild(document.createElement("span"))
+  setTimeout(() => {
+    d2.removeChild(s2)
+    setTimeout(() => {
+      d2.insertBefore(d3, s1)
+    }, 100)
+  }, 100)
+})
+</script>
+<style>
+.columns {
+  columns: 3;
+}
+.grid {
+  display: grid;
+  border:5px solid;
+  counter-reset: item;
+}
+span { display:contents; }
+span::before { content: counter(item) ":before"; }
+span::after { content: counter(item) ":after"; }
+</style>
+</head>
+<body>
+<div class=columns>
+<div class=grid>
+<c></c>
+<span><c></c></span>
+<span><c></c></span>
+</div>
+</div>
+</body>
+</html>

layout/generic/crashtests/crashtests.list

@@ -642,3 +642,5 @@ load 1278461-1.html
 load 1278461-2.html
 load 1304441.html
 load 1316649.html
+load 1381134.html
+load 1381134-2.html

layout/reftests/css-grid/reftest.list

@@ -251,7 +251,7 @@ asserts(0-10) == grid-fragmentation-015.html grid-fragmentation-015-ref.html # b
 != grid-fragmentation-dyn1-021.html grid-fragmentation-021-ref.html # bug 1251799
 == grid-fragmentation-dyn2-021.html grid-fragmentation-021-ref.html
 == grid-fragmentation-dyn3-021.html grid-fragmentation-021-ref.html
-asserts(1-10) == grid-fragmentation-dyn4-021.html grid-fragmentation-021-ref.html # assertion related to bug 1251799 ?
+== grid-fragmentation-dyn4-021.html grid-fragmentation-021-ref.html
 == grid-fragmentation-dyn5-021.html grid-fragmentation-021-ref.html
 == grid-fragmentation-dyn2-022.html grid-fragmentation-007-ref.html
 == grid-fragmentation-dyn1-023.html grid-fragmentation-023-ref.html