Subject: Re: git-daemon regression: 650c449250d7 common-main: call git_extract_argv0_path()

From: Mike Galbraith <[email-masked]>
Date: Sat, 26 Nov 2016 18:51:11 +0100

On Sat, 2016-11-26 at 12:09 -0500, Jeff King wrote:
> On Sat, Nov 26, 2016 at 03:03:48PM +0100, Mike Galbraith wrote:
> 
> > git-daemon went broke on me post v2.9.3 due to binaries being installed
> > in /usr/lib/git, which is not in PATH.  Reverting 650c449250d7 fixes it
> > up, as does ln -s /usr/lib/git/git-daemon /usr/bin/git-daemon 'course,
> > but thought I should report it, since it used to work without that.
> 
> Generally /usr/lib/git _should_ be in your PATH, as it is added by the
> git wrapper when you run "git daemon".
> 
> The only behavior difference caused by 650c449250d7 is that we replace
> argv[0] with the output of git_extract_argv0_path(argv[0]), which will
> give the basename, not a full path. So presumably you are running:
> 
>   /usr/lib/git/git-daemon
> 
> directly. I'm not sure that's even supposed to work these days, and it
> was not just a happy accident that it did.

Ah.  I'm using suse's rpm glue to package my modified source, and its
startup script still calls it directly, so wants some modernization.

> On the other hand, I am sympathetic that something used to work and now
> doesn't. It probably wouldn't be that hard to work around it.
> 
> The reason for the behavior change is that one of the cmd_main()
> functions was relying on the basename side-effect of the
> extract_argv0_path function, so 650c449250d7 just feeds the munged
> argv[0] to all of the programs. The cleanest fix would probably be
> something like:

That did fix it up, thanks.  I'll try twiddling the script instead.

> diff --git a/common-main.c b/common-main.c
> index 44a29e8b1..c654f9555 100644
> --- a/common-main.c
> +++ b/common-main.c
> @@ -33,7 +33,7 @@ int main(int argc, const char **argv)
>  
>  > 	> git_setup_gettext();
>  
> -> 	> argv[0] = git_extract_argv0_path(argv[0]);
> +> 	> git_extract_argv0_path(argv[0]);
>  
>  > 	> restore_sigpipe_to_default();
>  
> diff --git a/git.c b/git.c
> index bd66a2e0a..05986680c 100644
> --- a/git.c
> +++ b/git.c
> @@ -730,6 +730,11 @@ int cmd_main(int argc, const char **argv)
>  > 	> cmd = argv[0];
>  > 	> if (!cmd)
>  > 	> 	> cmd = "git-help";
> +> 	> else {
> +> 	> 	> const char *base = find_last_dir_sep(cmd);
> +> 	> 	> if (base)
> +> 	> 	> 	> cmd = base + 1;
> +> 	> }
>  
>  > 	> trace_command_performance(argv);
>  > 	> trace_stdin();
> 
> -Peff