[css-tables] Mark sibling cells dirty when a cell is added

third_party/WebKit/Source/core/layout/LayoutTableRow.cpp

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 135 matching lines @@
 
     if (beforeChild && beforeChild->parent() != this)
         beforeChild = splitAnonymousBoxesAroundChild(beforeChild);
 
     LayoutTableCell* cell = toLayoutTableCell(child);
 
     ASSERT(!beforeChild || beforeChild->isTableCell());
     LayoutTableBoxComponent::addChild(cell, beforeChild);
 
     // Generated content can result in us having a null section so make sure to null check our parent.
-    if (parent())
+    if (parent()) {
         section()->addCell(cell, this);
+        // When borders collapse, adding a cell can affect the the width of neighboring cells.
+        LayoutTable* enclosingTable = table();
+        if (enclosingTable && enclosingTable->collapseBorders()) {
+            if (LayoutTableCell* previousCell = cell->previousCell())
+                previousCell->setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::TableChanged);
+            if (LayoutTableCell* nextCell = cell->nextCell())
+                nextCell->setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::TableChanged);
+        }
+    }
 
     if (beforeChild || nextRow())
         section()->setNeedsCellRecalc();
 }
 
 void LayoutTableRow::layout()
 {
     ASSERT(needsLayout());
     LayoutAnalyzer::Scope analyzer(*this);
 
@@ skipping 97 matching lines @@
     // The cell and the row share the section's coordinate system. However
     // the visual overflow should be determined in the coordinate system of
     // the row, that's why we shift it below.
     LayoutUnit cellOffsetLogicalTopDifference = cell->location().y() - location().y();
     cellVisualOverflowRect.move(LayoutUnit(), cellOffsetLogicalTopDifference);
 
     addContentsVisualOverflow(cellVisualOverflowRect);
 }
 
 } // namespace blink