Re: format-patch subject-prefix gets truncated when using the --numbered flag

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 28, 2017, 17:42 UTC
Message-ID: <xmqqinnuky9e.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <1488297556.2955.11.camel@enea.com>

Adrian Dudau <Adrian.Dudau@enea.com> writes:

Show 5 quoted lines

> I noticed that the --subject-prefix string gets truncated sometimes,
> but only when using the --numbered flat. Here's an example:
>
> addu@sestofb11:/data/fb/addu/git$ export longm="very very very very
> very very very very very very very very very very long prefix"

This looks like "dr, my arm hurts when I twist it this way---don't do that then" ;-). Truncation is designed and intended to preserve space for the real title of commit.

Having said that...

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> This is happening on the latest master branch, so I dug through the
> code and tracked the issue to this piece of code in log-tree.c:
>
>         if (opt->total > 0) {
>                 static char buffer[64];
>                 snprintf(buffer, sizeof(buffer),
>                          "Subject: [%s%s%0*d/%d] ",
>                          opt->subject_prefix,
>                          *opt->subject_prefix ? " " : "",
>                          digits_in_number(opt->total),
>                          opt->nr, opt->total);
>                 subject = buffer;
>         } else if (opt->total == 0 && opt->subject_prefix && *opt-
>>subject_prefix) {
>                 static char buffer[256];
>                 snprintf(buffer, sizeof(buffer),
>                          "Subject: [%s] ",
>                          opt->subject_prefix);
>                 subject = buffer;
>         } else {
>                 subject = "Subject: ";
>         }
>
> Apparently the size of the "buffer" var is different in the two
> situations. Anybody knows if this is by design or just an old
> oversight?

I think this is just an old oversight. The latter should have been even shorter than the former one (or the former should be longer than the latter) to account for the width of the counter e.g. 01/27.