lib-vsprintf-optimize-put_dec_trunc8-fix

lib-vsprintf-optimize-put_dec_trunc8-fix

Rabin Vincent <rabin@rab.in> wrote:
> This patch breaks IP address printing with "%pI4" (and by extension,
> nfsroot).  Example:
>
>  - Before: 10.0.0.1
>  - After: 10...1

Mea culpa, and thank you for catching it!  As I said in my earlier
comment, I tested this most extensively wrapped by some sprintf code
that liked 0 converted to a 0-length string, as that works naturally
with the ANSI spec for %.0u.  And it turns out not to matter for the
usual printf code, as num_to_str special-cases that anyway.

The fix is straightforward:

Signed-off-by: George Spelvin <linux@horizon.com>
Cc: Rabin Vincent <rabin@rab.in>
Cc: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>