Change Range.getBoundingClientRect() when the first rect is empty

third_party/WebKit/Source/core/dom/Range.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Gunnstein Lye (gunnstein@netcom.no)
  * (C) 2000 Frederik Holljen (frederik.holljen@hig.no)
  * (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Motorola Mobility. 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 1564 matching lines @@
 }
 
 FloatRect Range::boundingRect() const
 {
     m_ownerDocument->updateLayoutIgnorePendingStylesheets();
 
     Vector<FloatQuad> quads;
     getBorderAndTextQuads(quads);
 
     FloatRect result;
-    // As per section 10 in https://www.w3.org/TR/cssom-view/
-    // "Return a static DOMRect object describing the smallest rectangle that
-    // includes the first rectangle in list and all of the remaining rectangles
-    // of which the height or width is not zero."
-    for (const FloatQuad& quad : quads) {
-        if (result.isEmpty())
-            result.uniteIfNonZero(quad.boundingBox());
-        else
-            result.unite(quad.boundingBox()); // Skips empty rects.
-    }
+    for (const FloatQuad& quad : quads)
+        result.unite(quad.boundingBox()); // Skips empty rects.
+
+    // If all rects are empty, return the first rect.
+    if (result.isEmpty() && !quads.isEmpty())
+        return quads.first().boundingBox();
 
     return result;
 }
 
 DEFINE_TRACE(Range)
 {
     visitor->trace(m_ownerDocument);
     visitor->trace(m_start);
     visitor->trace(m_end);
 }
 
 } // namespace blink
 
 #ifndef NDEBUG
 
 void showTree(const blink::Range* range)
 {
     if (range && range->boundaryPointsValid()) {
         range->startContainer()->showTreeAndMark(range->startContainer(), "S", range->endContainer(), "E");
         fprintf(stderr, "start offset: %d, end offset: %d\n", range->startOffset(), range->endOffset());
     } else {
         fprintf(stderr, "Cannot show tree if range is null, or if boundary points are invalid.\n");
     }
 }
 
 #endif