Col width is not honored when dynamically updated and it would not make table narrower

Source/core/rendering/RenderTableCol.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, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 33 matching lines @@
     updateFromElement();
 }
 
 void RenderTableCol::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     RenderBox::styleDidChange(diff, oldStyle);
 
     // If border was changed, notify table.
     if (parent()) {
         RenderTable* table = this->table();
-        if (table && !table->selfNeedsLayout() && !table->normalChildNeedsLayout() && oldStyle && oldStyle->border() != style()->border())
+        if (table && !table->selfNeedsLayout() && !table->normalChildNeedsLayout() && oldStyle && oldStyle->border() != style()->border()) {
             table->invalidateCollapsedBorders();
+        } else if (oldStyle && oldStyle->logicalWidth() != style()->logicalWidth()) {
+            unsigned nEffCols = table->numEffCols();
+            unsigned currentColumn = 0;
+            for (RenderTableCol* column = table->firstColumn()->nextColumn(); column; column = column->nextColumn()) {

[Julien - ping for review, 2014/02/14 18:18:37]

The logic skips the first column, is that intentional? Also is that really
correct with column-group (nextColumn returns the next column *or*
column-group)?

[Gurpreet, 2014/02/17 09:32:08]

The firstColumn would give the colgroup instead of col which is not what is
requried here. We want the col object so firstColumn()->nextColumn() would give
the first col and column->nextColumn() would give the next col.

+                if (this == column)
+                    break;
+                currentColumn += column->span();
+            }
+            unsigned currentColSpan = currentColumn + span();
+            for (unsigned j = currentColumn; j < currentColSpan && currentColSpan <= nEffCols; j++) {
+                for (unsigned i = 0; i < table->firstBody()->numRows(); i++) {

[Julien - ping for review, 2014/02/14 18:18:37]

You can't limit yourself to the first table-body as the other table sections are
impacted by a column change.

[Gurpreet, 2014/02/17 09:32:08]

Done.

+                    RenderTableCell* cell = table->firstBody()->primaryCellAt(i, j);
+                    if (!cell)
+                        continue;
+                    cell->setPreferredLogicalWidthsDirty();
+                }
+            }
+        }
     }
 }
 
 void RenderTableCol::updateFromElement()
 {
     unsigned oldSpan = m_span;
     Node* n = node();
     if (n && (n->hasTagName(colTag) || n->hasTagName(colgroupTag))) {
         HTMLTableColElement* tc = toHTMLTableColElement(n);
         m_span = tc->span();
@@ skipping 108 matching lines @@
     return style()->borderStart();
 }
 
 const BorderValue& RenderTableCol::borderAdjoiningCellAfter(const RenderTableCell* cell) const
 {
     ASSERT_UNUSED(cell, table()->colElement(cell->col() - 1) == this);
     return style()->borderEnd();
 }
 
 }