Underline Thickness is not uniform

Source/core/rendering/InlineFlowBox.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 1115 matching lines @@
     }
 
     if (paintInfo.phase == PaintPhaseMask)
         return;
 
     PaintPhase paintPhase = paintInfo.phase == PaintPhaseChildOutlines ? PaintPhaseOutline : paintInfo.phase;
     PaintInfo childInfo(paintInfo);
     childInfo.phase = paintPhase;
     childInfo.updatePaintingRootForChildren(&renderer());
 
-    // Paint our children.
+    float decorationThickness = 0;
+    float finalThickness = 0;
+    float maxDecorationThickness = 0;
+    float minDecorationThickness = 65536.0f;
+
+    // Paint our childrens and calculate underline thickness
     if (paintPhase != PaintPhaseSelfOutline) {
+        InlineBox * start = 0;
+        InlineBox * end = 0;
+
         for (InlineBox* curr = firstChild(); curr; curr = curr->nextOnLine()) {
-            if (curr->renderer().isText() || !curr->boxModelObject()->hasSelfPaintingLayer())
+            if (curr->renderer().isText() || !curr->boxModelObject()->hasSelfPaintingLayer()) {
                 curr->paint(childInfo, paintOffset, lineTop, lineBottom);
+                curr->getPaintDecorationSyle(childInfo, paintOffset, &decorationThickness);
+                if (decorationThickness) {
+                    if (maxDecorationThickness < decorationThickness)
+                        maxDecorationThickness = decorationThickness;
+
+                    if (minDecorationThickness > decorationThickness)
+                        minDecorationThickness = decorationThickness;
+
+                    if (!start)
+                        start = curr;
+                    end = curr;
+                } else if (end != start) {
+                    // found node where decoration style is not applied, ie; normal text node
+                    // lets apply uniform underline from start to end Text Nodes
+                    // We have underline thickness now, let draw it
+                    end = end->nextOnLine();
+                    finalThickness = (minDecorationThickness + maxDecorationThickness) / 2.0f;
+                    for (InlineBox* curr1 = start; curr1 != end; curr1 = curr1->nextOnLine())
+                        curr1->paintDecorationStyle(childInfo, paintOffset, lineTop, lineBottom, finalThickness);
+
+                    finalThickness = 0;
+                    maxDecorationThickness = 0;
+                    minDecorationThickness = 65536.0f;
+                    start = end = 0;
+                } else if ((decorationThickness) && (end == start)) {
+                    start->paintDecorationStyle(childInfo, paintOffset, lineTop, lineBottom, finalThickness);
+                    finalThickness = 0;
+                    maxDecorationThickness = 0;
+                    minDecorationThickness = 65536.0f;
+                    start = end = 0;
+                }
+            }
+        }
+
+        if (start && end) {
+            end = end->nextOnLine();
+            finalThickness = (minDecorationThickness + maxDecorationThickness) / 2.0f;
+            for (InlineBox* curr1 = start; curr1 != end; curr1 = curr1->nextOnLine())
+                curr1->paintDecorationStyle(childInfo, paintOffset, lineTop, lineBottom, finalThickness);
+
+            finalThickness = 0;
+            maxDecorationThickness = 0;
+            minDecorationThickness = 65536.0f;
+            start = end = 0;
         }
     }
 }
 
 void InlineFlowBox::paintFillLayers(const PaintInfo& paintInfo, const Color& c, const FillLayer* fillLayer, const LayoutRect& rect, CompositeOperator op)
 {
     if (!fillLayer)
         return;
     paintFillLayers(paintInfo, c, fillLayer->next(), rect, op);
     paintFillLayer(paintInfo, c, fillLayer, rect, op);
@@ skipping 492 matching lines @@
         ASSERT(child->prevOnLine() == prev);
         prev = child;
     }
     ASSERT(prev == m_lastChild);
 #endif
 }
 
 #endif
 
 } // namespace WebCore