Bug 1461812 - Make sure we fully cleanup any partially constructed display lists when returning a failure from AttemptPartialUpdate. r=miko

MozReview-Commit-ID: DJBG6UFcoyR

--HG--
extra : rebase_source : 38e33ad785556b92b8058f00a85d48c27fb4d2e3

layout/base/crashtests/1461812.html

@@ -0,0 +1,19 @@
+<style>
+:not(feConvolveMatrix) {
+  width: -moz-max-content;
+  column-width: 0em;
+  text-indent: 1pt;
+}
+.cl {
+  padding-bottom: 93vw;
+}
+</style>
+<script>
+function go() {
+  b.appendChild(a);
+}
+</script>
+<marquee id="b">4H</marquee>
+<details class="cl">
+<summary id="a" style="mix-blend-mode:color-dodge">A</summary>
+<style onload="go()">

layout/base/crashtests/crashtests.list

@@ -531,3 +531,4 @@ load 1453702.html
 load 1453342.html
 load 1453196.html
 pref(dom.webcomponents.shadowdom.enabled,true) load 1414303.html
+load 1461812.html

layout/painting/RetainedDisplayListBuilder.cpp

@@ -463,11 +463,6 @@ public:
   bool mResultIsModified;
 };
 
-void RetainedDisplayList::ClearDAG()
-{
-  mDAG.Clear();
-}
-
 /**
  * Takes two display lists and merges them into an output list.
  *
@@ -1119,7 +1114,7 @@ RetainedDisplayListBuilder::AttemptPartialUpdate(
                            &modifiedAGR, framesWithProps.Frames()) ||
       !PreProcessDisplayList(&mList, modifiedAGR)) {
     mBuilder.LeavePresShell(mBuilder.RootReferenceFrame(), List());
-    mList.ClearDAG();
+    mList.DeleteAll(&mBuilder);
     return PartialUpdateResult::Failed;
   }
 
@@ -1157,7 +1152,8 @@ RetainedDisplayListBuilder::AttemptPartialUpdate(
   if (mBuilder.PartialBuildFailed()) {
     mBuilder.SetPartialBuildFailed(false);
     mBuilder.LeavePresShell(mBuilder.RootReferenceFrame(), List());
-    mList.ClearDAG();
+    mList.DeleteAll(&mBuilder);
+    modifiedDL.DeleteAll(&mBuilder);
     return PartialUpdateResult::Failed;
   }
 

layout/painting/nsDisplayList.h

@@ -3474,11 +3474,10 @@ public:
       }
     }
     mOldItems.Clear();
+    mDAG.Clear();
     nsDisplayList::DeleteAll(aBuilder);
   }
 
-  void ClearDAG();
-
   DirectedAcyclicGraph<MergedListUnits> mDAG;
 
   // Temporary state initialized during the preprocess pass