Fix invalid selection produced when dragging mouse outside the SVG text element

third_party/WebKit/Source/core/layout/svg/LayoutSVGText.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2006 Alexander Kellett <lypanov@kde.org>
  * Copyright (C) 2006 Oliver Hunt <ojh16@student.canterbury.ac.nz>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved.
  * Copyright (C) 2012 Google Inc.
  *
@@ skipping 434 matching lines @@
 
     return false;
 }
 
 PositionWithAffinity LayoutSVGText::positionForPoint(const LayoutPoint& pointInContents)
 {
     RootInlineBox* rootBox = firstRootBox();
     if (!rootBox)
         return createPositionWithAffinity(0);
 
+    LayoutPoint clippedPointInContents(pointInContents);
+    clippedPointInContents.clampNegativeToZero();
+
     ASSERT(!rootBox->nextRootBox());
     ASSERT(childrenInline());
 
-    InlineBox* closestBox = toSVGRootInlineBox(rootBox)->closestLeafChildForPosition(pointInContents);
+    InlineBox* closestBox = toSVGRootInlineBox(rootBox)->closestLeafChildForPosition(clippedPointInContents);
     if (!closestBox)
         return createPositionWithAffinity(0);
 
-    return closestBox->lineLayoutItem().positionForPoint(LayoutPoint(pointInContents.x(), closestBox->y()));
+    return closestBox->lineLayoutItem().positionForPoint(LayoutPoint(clippedPointInContents.x(), closestBox->y()));
 }
 
 void LayoutSVGText::absoluteQuads(Vector<FloatQuad>& quads, bool* wasFixed) const
 {
     quads.append(localToAbsoluteQuad(strokeBoundingBox(), 0 /* mode */, wasFixed));
 }
 
 void LayoutSVGText::paint(const PaintInfo& paintInfo, const LayoutPoint&) const
 {
     SVGTextPainter(*this).paint(paintInfo);
@@ skipping 63 matching lines @@
         paintInvalidationState.pushDelayedPaintInvalidationTarget(*this);
 
     ForceHorriblySlowRectMapping slowRectMapping(&paintInvalidationState);
     PaintInvalidationState childTreeWalkState(paintInvalidationState, *this, paintInvalidationState.paintInvalidationContainer());
     if (reason == PaintInvalidationSVGResourceChange)
         childTreeWalkState.setForceSubtreeInvalidationWithinContainer();
     invalidatePaintOfSubtreesIfNeeded(childTreeWalkState);
 }
 
 } // namespace blink