OmniboxView: Attempt to fix a crash in GetSelectedText().

chrome/browser/ui/views/omnibox/omnibox_view_win.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/ui/views/omnibox/omnibox_view_win.h"
 
 #include <algorithm>
 #include <locale>
 #include <string>
 
@@ skipping 593 matching lines @@
   // synchronously change the permanent text to the new URL.  If we don't freeze
   // here, the user could potentially see a flicker of the current URL before
   // the new one reappears, which would look glitchy.
   ScopedFreeze freeze(this, GetTextObjectModel());
   model_->OpenMatch(match, disposition, alternate_nav_url,
                     selected_line, keyword);
 }
 
 string16 OmniboxViewWin::GetText() const {
   const int len = GetTextLength() + 1;
+  if (len <= 1)
+    return string16();
+
   string16 str;
   GetWindowText(WriteInto(&str, len), len);
   return str;
 }
 
 bool OmniboxViewWin::IsEditingOrEmpty() const {
   return model_->user_input_in_progress() || (GetTextLength() == 0);
 }
 
 int OmniboxViewWin::GetIcon() const {
@@ skipping 1478 matching lines @@
   long flags;
   selection->GetFlags(&flags);
   if (flags & tomSelStartActive)
     std::swap(sel.cpMin, sel.cpMax);
 }
 
 string16 OmniboxViewWin::GetSelectedText() const {
   // Figure out the length of the selection.
   CHARRANGE sel;
   GetSel(sel);
+  if (sel.cpMin == sel.cpMax)  // GetSelText() crashes on NULL input.
+    return string16();
 
   // Grab the selected text.
   string16 str;
   GetSelText(WriteInto(&str, sel.cpMax - sel.cpMin + 1));
   return str;
 }
 
 void OmniboxViewWin::SetSelection(LONG start, LONG end) {
   SetSel(start, end);
 
@@ skipping 516 matching lines @@
   // PosFromChar(i) might return 0 when i is greater than 1.
   return font_.GetStringWidth(text) + GetHorizontalMargin();
 }
 
 bool OmniboxViewWin::IsCaretAtEnd() const {
   long length = GetTextLength();
   CHARRANGE sel;
   GetSelection(sel);
   return sel.cpMin == sel.cpMax && sel.cpMin == length;
 }