Unreviewed, fix Mac release build.

* page/CaptionUserPreferencesMac.mm:
(WebCore::languageIdentifier):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@146385 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

+2013-03-20  Eric Carlson  <eric.carlson@apple.com>
+
+        Unreviewed, fix Mac release build.
+
+        * page/CaptionUserPreferencesMac.mm:
+        (WebCore::languageIdentifier):
+
 2013-03-20  Eric Carlson  <eric.carlson@apple.com>
         Allow ports specific text track menu

Source/WebCore/page/CaptionUserPreferencesMac.mm

@@ -590,8 +590,9 @@ static String languageIdentifier(const String& languageCode)
         return languageCode;
 
     String lowercaseLanguageCode = languageCode.lower();
-    
-    if (lowercaseLanguageCode.length() >= 3 && (lowercaseLanguageCode[2] == '_' || lowercaseLanguageCode[2] == '-'))
+
+    // Need 2U here to disambiguate String::operator[] from operator(NSString*, int)[] in a production build.
+    if (lowercaseLanguageCode.length() >= 3 && (lowercaseLanguageCode[2U] == '_' || lowercaseLanguageCode[2U] == '-'))
         lowercaseLanguageCode.truncate(2);
     
     return lowercaseLanguageCode;