Comment 15 for bug 1109327

My pleasure. Per N1256 (C99+TC1/2/3):

s
If no l length modifier is present, the argument shall be a pointer to the initial element of an array of character type.246) Characters from the array are written up to (but not including) the terminating null character. If the precision is specified, no more than that many bytes are written. If the precision is not specified or is greater than the size of the array, the array shall contain a null character. If an l length modifier is present, the argument shall be a pointer to the initial element of an array of wchar_t type. Wide characters from the array are converted to multibyte characters (each as if by a call to the wcrtomb function, with the conversion state described by an mbstate_t object initialized to zero before the first wide character is converted) up to and including a terminating null wide character. The resulting multibyte characters are written up to (but not including) the terminating null character (byte). If no precision is specified, the array shall contain a null wide character. If a precision is specified, no more than that many bytes are written (including shift sequences, if any), and the array shall contain a null wide character if, to equal the multibyte character sequence length given by the precision, the function would need to access a wide character one past the end of the array. In no case is a partial multibyte character written.247)

And the referenced footnotes:

246) No special provisions are made for multibyte characters.

247) Redundant shift sequences may result if multibyte characters have a state-dependent encoding.

I don't think it could be clearer than what footnote 246 says about %s without the l modifier.