Re: [PATCH 2/7] nfv?asprintf are broken without va_copy, workaround them.

[Junio C Hamano <gitster@pobox.com>]

Pierre Habouzit <madcoder@debian.org> writes:

> * drop nfasprintf.
> * move nfvasprintf into imap-send.c back, and let it work on a 8k buffer,
>   and die() in case of overflow. It should be enough for imap commands, if
>   someone cares about imap-send, he's welcomed to fix it properly.
> * replace nfvasprintf use in merge-recursive with a copy of the strbuf_addf
>   logic, it's one place, we'll live with it.
>   To ease the change, output_buffer string list is replaced with a strbuf ;)

While I'd agree with all of the above,

> * rework trace.c API's so that only one of the trace functions takes a
>   vararg. It's used to format strerror()s and git command names, it should
>   never be more than a few octets long, let it work on a 8k static buffer
>   with vsnprintf or die loudly.

and I'd agree with this in principle, there is a minor nit with
the implementation and use in trace.c.  E.g.

> diff --git a/exec_cmd.c b/exec_cmd.c
> index 9b74ed2..c0f954e 100644
> --- a/exec_cmd.c
> +++ b/exec_cmd.c
> @@ -97,7 +97,8 @@ int execv_git_cmd(const char **argv)
>  		tmp = argv[0];
>  		argv[0] = git_command;
>  
> -		trace_argv_printf(argv, -1, "trace: exec:");
> +		trace_printf("trace: exec:");
> +		trace_argv(argv, -1);

This used to be a single call into trace.c which would format a
single string to write(2) out.  Now these two messages go
through separate write(2) and can be broken up.  I think the
atomicity of the log/trace message was the primary reason the
original had such a strange calling convention.