Let RenderTable reach table cells needing overflow recalc

Source/core/rendering/RenderObject.cpp

Index: Source/core/rendering/RenderObject.cpp
diff --git a/Source/core/rendering/RenderObject.cpp b/Source/core/rendering/RenderObject.cpp
index ff25785b44017adb01740cf240ed9a6f6d028013..ea8d42c7dad74b6c18d0b76d606892304290f3e0 100644
--- a/Source/core/rendering/RenderObject.cpp
+++ b/Source/core/rendering/RenderObject.cpp
@@ -1614,18 +1614,26 @@ void RenderObject::setPseudoStyle(PassRefPtr<RenderStyle> pseudoStyle)
     setStyle(pseudoStyle);
 }
 
-void RenderObject::markContainingBlocksForOverflowRecalc()
+static RenderObject* containerForOverflowRecalc(const RenderObject* object)
 {
-    for (RenderBlock* container = containingBlock(); container && !container->childNeedsOverflowRecalcAfterStyleChange(); container = container->containingBlock())
-        container->setChildNeedsOverflowRecalcAfterStyleChange(true);
+    // For table parts, we let the parent (e.g. RenderTableRow for RenderTableCell)
+    // handle the childNeedsOverflowRecalcAfterStyleChange flag, because
+    // RenderBlock::recalcChildOverflowAfterStyleChange() may not reach the table parts.
+    return object->isTablePart() ? object->parent() : object->containingBlock();
+}

[Julien - ping for review, 2014/11/25 18:33:10]

:(

Wouldn't container() work without needing this logic?

Also what you really need to do is propagate the needs-overflow-computation flag
from RenderTableCell::styleDidChange. That would require a lot less
modifications.

[Xianzhu, 2014/11/25 20:17:12]

This seems not the best because we'll set the flag on unnecessary objects which
won't handle the flag, and leave the flag uncleared.

How about renaming the function to markContainersForOverflowRecalcIfNeeded()
which reflect the fact that we are not marking all containers.
styleDidChange doesn't work for the test case because
RenderTableCell::styleDidChange won't be called when its descendant needs
overflow recalc.

+
+void RenderObject::markContainersForOverflowRecalc()

[Julien - ping for review, 2014/11/25 18:33:10]

If you put container in the name, I would have expected you to use container().

+{
+    for (RenderObject* container = containerForOverflowRecalc(this); container && !container->childNeedsOverflowRecalcAfterStyleChange(); container = containerForOverflowRecalc(container))
+        container->setChildNeedsOverflowRecalcAfterStyleChange();
 }
 
 void RenderObject::setNeedsOverflowRecalcAfterStyleChange()
 {
     bool neededRecalc = needsOverflowRecalcAfterStyleChange();
-    setSelfNeedsOverflowRecalcAfterStyleChange(true);
+    setSelfNeedsOverflowRecalcAfterStyleChange();
     if (!neededRecalc)
-        markContainingBlocksForOverflowRecalc();
+        markContainersForOverflowRecalc();
 }
 
 void RenderObject::setStyle(PassRefPtr<RenderStyle> style)
@@ -1827,7 +1835,7 @@ void RenderObject::styleDidChange(StyleDifference diff, const RenderStyle* oldSt
 
         // Ditto.
         if (needsOverflowRecalcAfterStyleChange() && oldStyle->position() != m_style->position())
-            markContainingBlocksForOverflowRecalc();
+            markContainersForOverflowRecalc();
 
         if (diff.needsFullLayout())
             setNeedsLayoutAndPrefWidthsRecalc();