Try to show the full ellipsis at all times

third_party/WebKit/Source/core/layout/line/InlineTextBox.cpp

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 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.
@@ skipping 345 matching lines @@
     bool ltr = isLeftToRightDirection();
     if (ltr != flowIsLTR) {
       // Width in pixels of the visible portion of the box, excluding the
       // ellipsis.
       LayoutUnit visibleBoxWidth =
           visibleRightEdge - visibleLeftEdge - ellipsisWidth;
       ellipsisX = flowIsLTR ? adjustedLogicalLeft + visibleBoxWidth
                             : logicalRight() - visibleBoxWidth;
     }
 
-    // The box's width includes partial glyphs, so respect that when placing
-    // the ellipsis.
-    int offset = offsetForPosition(ellipsisX);
+    // We measure the text using the second half of the previous character and
+    // the first half of the current one when the text is rtl. This gives a
+    // more accurate position in rtl text.
+    int offset = offsetForPosition(ellipsisX, !ltr);
     // Full truncation is only necessary when we're flowing left-to-right.
     if (flowIsLTR && offset == 0 && ltr == flowIsLTR) {
       // No characters should be laid out.  Set ourselves to full truncation and
       // place the ellipsis at the min of our start and the ellipsis edge.
       setTruncation(cFullTruncation);
       truncatedWidth += ellipsisWidth;
       return std::min(ellipsisX, logicalLeft());
     }
 
+    // When the text's direction doesn't match the flow's direction we can
+    // choose an offset that starts outside the visible box: compensate for that
+    // if necessary.
+    if (flowIsLTR != ltr && logicalLeft() < 0 && offset >= m_start &&
+        positionForOffset(offset) < logicalLeft().abs())
+      offset++;
+
     // Set the truncation index on the text run.
     setTruncation(offset);
 
     // If we got here that means that we were only partially truncated and we
     // need to return the pixel offset at which to place the ellipsis. Where the
     // text and its flow have opposite directions then our offset into the text
     // is at the start of the part that will be visible.
     LayoutUnit widthOfVisibleText(getLineLayoutItem().width(
         ltr == flowIsLTR ? m_start : m_start + offset,
         ltr == flowIsLTR ? offset : m_len - offset, textPos(),
@@ skipping 305 matching lines @@
   const int layoutObjectCharacterOffset = 75;
   for (; printedCharacters < layoutObjectCharacterOffset; printedCharacters++)
     fputc(' ', stderr);
   fprintf(stderr, "(%d,%d) \"%s\"\n", start(), start() + len(),
           value.utf8().data());
 }
 
 #endif
 
 }  // namespace blink