Restore only the collapsed leading space when copy text

third_party/WebKit/Source/core/editing/iterators/TextIterator.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2005 Alexey Proskuryakov.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 597 matching lines @@
                         spliceBuffer(spaceCharacter, m_node, 0, runStart, runStart + 1);
                     m_offset = runStart + 1;
                 } else {
                     size_t subrunEnd = str.find('\n', runStart);
                     if (subrunEnd == kNotFound || subrunEnd > runEnd) {
                         subrunEnd = runEnd;
                         // Restore the collapsed space for copy & paste.
                         // See http://crbug.com/318925
                         // For trailing space.
                         if (!nextTextBox && m_textBox->root().nextRootBox() && m_textBox->root().lastChild() == m_textBox) {
-                            if (str.endsWith(' ') && subrunEnd == str.length() - 1 && str[subrunEnd - 1] != ' ')
-                                ++subrunEnd;
+                            if (str.endsWith(' ') && subrunEnd == str.length() - 1 && str[subrunEnd - 1] != ' ') {
+                                // If there is the leading space in the next line, we don't need to restore the trailing space.
+                                // Example: <div style="width: 2em;"><b><i>foo </i></b> bar</div>
+                                String textOfNextline = m_textBox->root().nextRootBox()->firstChild()->getLineLayoutItem().node()->nodeValue();
+                                if (textOfNextline[0] != ' ')
+                                    ++subrunEnd;
+                            }
                         }
                         // For leading space.
                         if (!emitsImageAltText() && !doesNotBreakAtReplacedElement() && !forInnerText()
                             && m_textBox->root().prevRootBox() && m_textBox->root().firstChild() == m_textBox) {
                             InlineBox* lastChildOfPrevRoot = m_textBox->root().prevRootBox()->lastChild();
                             if (m_textBox->getLineLayoutItem() != lastChildOfPrevRoot->getLineLayoutItem() && !lastChildOfPrevRoot->getLineLayoutItem().isBR()
                                 && !lastChildOfPrevRoot->isInlineFlowBox()) {
                                 if (runStart > 0 && str[0] == ' ' && str[1] != ' ')
                                     --runStart;
                             }
@@ skipping 587 matching lines @@
 
 String plainText(const EphemeralRangeInFlatTree& range, TextIteratorBehaviorFlags behavior)
 {
     return createPlainText<EditingInFlatTreeStrategy>(range, behavior);
 }
 
 template class CORE_TEMPLATE_EXPORT TextIteratorAlgorithm<EditingStrategy>;
 template class CORE_TEMPLATE_EXPORT TextIteratorAlgorithm<EditingInFlatTreeStrategy>;
 
 } // namespace blink