Re: printf and -m

["James K. Lowden" <jklowden%schemamania.org@localhost>]

On Tue, 25 Aug 2015 11:20:59 -0400 (EDT)
Mouse <mouse%Rodents-Montreal.ORG@localhost> wrote:

> Perhaps jkl would also argue that the C standard is equally irrelevant
> here, but I think that argument has to be made, not silently assumed.

Thanks for pointing that out, Mouse.  Section 7.19.6.1,
paragraph 9 says, "If a conversion specification is invalid, the
behavior is undefined."  The patch just changes what form "undefined"
takes in the case of %m.  

> In particular, this patch also makes it easier to write nonportable
> code and harder to catch it, because it will let %m slip through,

IMO this is better diagnosed by the compiler with something like 
gcc's -ansi option.  As it happens, -ansi does *not* (in my testing)
produce a warning when %m is present.  I think they might consider that
a bug. I'm willing to file a PR for that with them.  

--jkl