Fix infinite loop caused by ElideText()

ui/base/text/text_elider.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file implements utility functions for eliding and formatting UI text.
 //
 // Note that several of the functions declared in text_elider.h are implemented
 // in this file using helper classes in an unnamed namespace.
 
 #include "ui/base/text/text_elider.h"
@@ skipping 30 matching lines @@
 class StringSlicer {
  public:
   StringSlicer(const string16& text,
                const string16& ellipsis,
                bool elide_in_middle)
       : text_(text),
         ellipsis_(ellipsis),
         elide_in_middle_(elide_in_middle) {
   }
 
-  // Cuts |text_| to be |length| characters long.  If |cut_in_middle_| is true,
+  // Cuts |text_| to be |length| characters long. If |elide_in_middle_| is true,
   // the middle of the string is removed to leave equal-length pieces from the
   // beginning and end of the string; otherwise, the end of the string is
-  // removed and only the beginning remains.  If |insert_ellipsis| is true,
-  // then an ellipsis character will by inserted at the cut point.
+  // removed and only the beginning remains. If |insert_ellipsis| is true,
+  // then an ellipsis character will be inserted at the cut point.
   string16 CutString(size_t length, bool insert_ellipsis) {
     const string16 ellipsis_text = insert_ellipsis ? ellipsis_ : string16();
 
     if (!elide_in_middle_)
       return text_.substr(0, FindValidBoundaryBefore(length)) + ellipsis_text;
 
     // We put the extra character, if any, before the cut.
     const size_t half_length = length / 2;
     const size_t prefix_length = FindValidBoundaryBefore(length - half_length);
     const size_t suffix_start_guess = text_.length() - half_length;
@@ skipping 405 matching lines @@
   // (eliding way too much from a ridiculous string is probably still
   // ridiculous), but we should check other widths for bogus values as well.
   if (current_text_pixel_width <= 0 && !text.empty()) {
     const string16 cut = slicer.CutString(text.length() / 2, false);
     return ElideText(cut, font, available_pixel_width, elide_behavior);
   }
 
   if (current_text_pixel_width <= available_pixel_width)
     return text;
 
-  if (font.GetStringWidth(kEllipsisUTF16) > available_pixel_width)
+  if (insert_ellipsis &&
+      font.GetStringWidth(kEllipsisUTF16) > available_pixel_width)
     return string16();
 
   // Use binary search to compute the elided text.
   size_t lo = 0;
   size_t hi = text.length() - 1;
   size_t guess;
   for (guess = (lo + hi) / 2; lo <= hi; guess = (lo + hi) / 2) {
     // We check the length of the whole desired string at once to ensure we
     // handle kerning/ligatures/etc. correctly.
     const string16 cut = slicer.CutString(guess, insert_ellipsis);
@@ skipping 454 matching lines @@
   // Account for naturally-occuring newlines.
   NewLine();
 }
 
 int RectangleText::WrapWord(const string16& word) {
   // Word is so wide that it must be fragmented.
   string16 text = word;
   int lines_added = 0;
   bool first_fragment = true;
   while (!insufficient_height_ && !text.empty()) {
-    const string16 fragment =
+    string16 fragment =
         ui::ElideText(text, font_, available_pixel_width_, ui::TRUNCATE_AT_END);
+    // At least one character has to be added at every line, even if the
+    // available space is too small.
+    if(fragment.empty())
+      fragment = text.substr(0, 1);
     if (!first_fragment && NewLine())
       lines_added++;
     AddToCurrentLine(fragment);
     text = text.substr(fragment.length());
     first_fragment = false;
   }
   return lines_added;
 }
 
 int RectangleText::AddWordOverflow(const string16& word) {
@@ skipping 154 matching lines @@
       index = char_iterator.getIndex();
     } else {
       // String has leading whitespace, return the elide string.
       return kElideString;
     }
   }
   return string.substr(0, index) + kElideString;
 }
 
 }  // namespace ui