svn commit: r234528 - head/lib/libc/stdio

Peter Jeremy peterjeremy at
Sat Apr 21 07:07:12 UTC 2012

On 2012-Apr-21 06:08:02 +0000, David Schultz <das at> wrote:
>  Fix a bug introduced in r187302 that was causing fputws() to enter an
>  infinite loop pretty much unconditionally.

Unfortunately, I suspect you've just turned an unconditional infinite
loop into a conditional one.  There's still a "wsp = ws;" inside the
loop so if you pass in a long string (one that exceeds BUFSIZ bytes
when converted to a multi-byte string) then wsp will be non-NULL
after the call to __wcsnrtombs(), causing the do loop to loop and
then wsp will be re-initialised to ws.  I think the fix is to move
the "wsp = ws;" outside the loop.

>  It's remarkable that the
>  patch that introduced the bug was never tested, but even more
>  remarkable that nobody noticed for over two years.

It took me a while to work out that the problem was libc and not my code.

Peter Jeremy
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