Make LayoutText::absoluteQuadsForRange to consider leading/trailing whitespaces

Source/core/layout/LayoutText.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * 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
@@ skipping 423 matching lines @@
     // Work around signed/unsigned issues. This function takes unsigneds, and is often passed UINT_MAX
     // to mean "all the way to the end". InlineTextBox coordinates are unsigneds, so changing this
     // function to take ints causes various internal mismatches. But selectionRect takes ints, and
     // passing UINT_MAX to it causes trouble. Ideally we'd change selectionRect to take unsigneds, but
     // that would cause many ripple effects, so for now we'll just clamp our unsigned parameters to INT_MAX.
     ASSERT(end == UINT_MAX || end <= INT_MAX);
     ASSERT(start <= INT_MAX);
     start = std::min(start, static_cast<unsigned>(INT_MAX));
     end = std::min(end, static_cast<unsigned>(INT_MAX));
 
+    const unsigned caretMinOffset = static_cast<unsigned>(this->caretMinOffset());
+    const unsigned caretMaxOffset = static_cast<unsigned>(this->caretMaxOffset());
+
+    // Narrows |start| and |end| into |caretMinOffset| and |careMaxOffset|
+    // to ignore unrendered leading and trailing whitespaces.
+    start = std::min(std::max(caretMinOffset, start), caretMaxOffset);
+    end = std::min(std::max(caretMinOffset, end), caretMaxOffset);
+
     for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
         // Note: box->end() returns the index of the last character, not the index past it
         if (start <= box->start() && box->end() < end) {
             LayoutRect r(box->calculateBoundaries());
             if (useSelectionHeight) {
                 LayoutRect selectionRect = box->localSelectionRect(start, end);
                 if (box->isHorizontal()) {
                     r.setHeight(selectionRect.height());
                     r.setY(selectionRect.y());
                 } else {
@@ skipping 1422 matching lines @@
     for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
         paintInvalidationContainer.invalidateDisplayItemClientOnBacking(*box);
         if (box->truncation() != cNoTruncation) {
             if (EllipsisBox* ellipsisBox = box->root().ellipsisBox())
                 paintInvalidationContainer.invalidateDisplayItemClientOnBacking(*ellipsisBox);
         }
     }
 }
 
 } // namespace blink