Fix wrong PaintInvalidationIncremental on empty object

The bug was because LayoutBox::getPaintInvalidatinReason() returned PaintInvalidationIncremental after LayoutObject::getPaintInvalidationReason() returned PaintInvalidationNone for an empty object. In the case we should not do any paint invalidation but executed incrementallyInvalidatePaint() and triggered the assertion failure. BUG=634807 Review-Url: https://codereview.chromium.org/2212223004 Cr-Commit-Position: refs/heads/master@{#410231}
marcosholgado · Aug 6, 2016 · b9ec37c · b9ec37c
1 parent b886659
commit b9ec37c
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Showing 3 changed files with 29 additions and 2 deletions.
diff --git a/third_party/WebKit/LayoutTests/paint/invalidation/empty-object-move-and-resize-expected.txt b/third_party/WebKit/LayoutTests/paint/invalidation/empty-object-move-and-resize-expected.txt
@@ -0,0 +1,13 @@
+{
+  "name": "Content Root Layer",
+  "bounds": [800, 600],
+  "children": [
+    {
+      "name": "LayoutView #document",
+      "bounds": [800, 600],
+      "contentsOpaque": true,
+      "drawsContent": true
+    }
+  ]
+}
+
diff --git a/third_party/WebKit/LayoutTests/paint/invalidation/empty-object-move-and-resize.html b/third_party/WebKit/LayoutTests/paint/invalidation/empty-object-move-and-resize.html
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<script src="../../fast/repaint/resources/text-based-repaint.js"></script>
+<script>
+function repaintTest() {
+  target.style.top = '200px';
+  target.style.left = '200px';
+  target.style.width = '200px';
+  target.style.height = '200px';
+}
+onload = runRepaintTest;
+</script>
+Tests paint invalidation of an empty object when moved and resized.
+It passes if there is not any assertion failure or paint invalidation.
+<div id="target" style="position: absolute; top: 100px; left: 100px; width: 100px; height: 100px"></div>
diff --git a/third_party/WebKit/Source/core/layout/LayoutBox.cpp b/third_party/WebKit/Source/core/layout/LayoutBox.cpp
@@ -2043,7 +2043,7 @@ bool LayoutBox::paintedOutputOfObjectHasNoEffect() const
         return false;
 
     // Cannot skip paint invalidation if the box has real things to paint.
-    if (getSelectionState() != SelectionNone || hasBoxDecorationBackground() || styleRef().hasVisualOverflowingEffect())
+    if (getSelectionState() != SelectionNone || hasBoxDecorationBackground() || styleRef().hasBoxDecorations() || styleRef().hasVisualOverflowingEffect())
         return false;
 
     // If the box has clip, we need issue a paint invalidation to cover the changed part of
@@ -4056,7 +4056,7 @@ PaintInvalidationReason LayoutBox::getPaintInvalidationReason(const PaintInvalid
     if (oldBorderBoxSize.height() != newBorderBoxSize.height() && mustInvalidateBackgroundOrBorderPaintOnHeightChange())
         return PaintInvalidationBorderBoxChange;
 
-    return PaintInvalidationIncremental;
+    return styleRef().hasBackground() || styleRef().hasBoxDecorations() ? PaintInvalidationIncremental : invalidationReason;
 }
 
 void LayoutBox::incrementallyInvalidatePaint(const LayoutBoxModelObject& paintInvalidationContainer, const LayoutRect& oldBounds, const LayoutRect& newBounds, const LayoutPoint& positionFromPaintInvalidationBacking)