diff --git a/dlls/msvcrt/mbcs.c b/dlls/msvcrt/mbcs.c index ac458817e29f3a53a0214f358b35ea6a2589d706..a8cd2372ccc9e07c3faa816a341affb8dff7abf8 100644 --- a/dlls/msvcrt/mbcs.c +++ b/dlls/msvcrt/mbcs.c @@ -1858,15 +1858,14 @@ MSVCRT_size_t CDECL _mbstrlen_l(const char* str, MSVCRT__locale_t locale) locinfo = locale->locinfo; if(locinfo->mb_cur_max > 1) { - MSVCRT_size_t len = 0; - while(*str) { - /* FIXME: According to the documentation we are supposed to test for - * multi-byte character validity. Whatever that means - */ - str += MSVCRT_isleadbyte(*str) ? 2 : 1; - len++; + MSVCRT_size_t len; + len = MultiByteToWideChar(locinfo->lc_codepage, MB_ERR_INVALID_CHARS, + str, -1, NULL, 0); + if (!len) { + *MSVCRT__errno() = MSVCRT_EILSEQ; + return -1; } - return len; + return len - 1; } return strlen(str);