This SO question: http://stackoverflow.com/questions/15344402/how-can-i-read-a-0xff-in-a-file-with-libc-istream-iterator/15347225#15347225 highlighted the lack of a cast in the implementation of std::cin. Added. I unfortunately don't have a test case to add to the suite since this bug only shows itself when using std::cin. The current testsuite setup does not have a way a good way to test std::cin.

llvm-svn: 176822

libcxx/include/__std_stream

@@ -150,7 +150,7 @@ __stdinbuf<_CharT>::__getchar(bool __consume)
     {
         for (int __i = __nread; __i > 0;)
         {
-            if (ungetc(__extbuf[--__i], __file_) == EOF)
+            if (ungetc(traits_type::to_int_type(__extbuf[--__i]), __file_) == EOF)
                 return traits_type::eof();
         }
     }