Re: ftp: Cleanup port number to string conversion.

[Collin Funk]

Hi Erik,

Erik Auerswald <auerswal@unix-ag.uni-kl.de> writes:

>> Thanks for looking into fixing warnings! :-)

There are many of them, so feel free to work on them. I won't be angry
if you finish fixing them before me. :)

>> > -  snprintf (portstr, sizeof (portstr) - 1, "%u", port);
>> > +  sprintf (portstr, "%u", port);
>> >    memset (&hisctladdr, 0, sizeof (hisctladdr));
>> >    memset (&hints, 0, sizeof (hints));
>> >  
>> 
>> I prefer the original code with snprintf() here, because it directly
>> shows that it does not overflow the buffer and that the last byte of
>> the buffer is unchanged.
>
> I'd still prefer keeping snprintf() here.

I was going to disagree since that macro allows all values between 0 -
65535.

However, I saw an old thread on bug-gnulib@gnu.org [1]. Apparently,
POSIX requires '%d' to use the portable character set (which grantees 1
byte per character). Other specifiers can do as they wish.

In practice, I don't think it should ever be a problem. But I guess
snprintf would be safer in that case...

Applied the patch changing the sprintf to:

+  snprintf (portstr, sizeof portstr, "%u", port);

Patch attached. Feel free to make changes if you see fit.

Collin

[1] https://lists.gnu.org/archive/html/bug-gnulib/2011-02/msg00119.html

0001-ftp-Cleanup-port-number-to-string-conversion.patch
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