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

Source/core/rendering/RenderTableCol.cpp

Index: Source/core/rendering/RenderTableCol.cpp
diff --git a/Source/core/rendering/RenderTableCol.cpp b/Source/core/rendering/RenderTableCol.cpp
index 26c5935f97f1d3bd065cfbc31b1acc90e6fc6c8a..32f48e992d2bf212682b78593715c1bed60a1195 100644
--- a/Source/core/rendering/RenderTableCol.cpp
+++ b/Source/core/rendering/RenderTableCol.cpp
@@ -51,8 +51,26 @@ void RenderTableCol::styleDidChange(StyleDifference diff, const RenderStyle* old
     // 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();
+                }
+            }
+        }
     }
 }