Re: [PATCH v2] git svn : hook before 'git svn dcommit'

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 15, 2011, 21:14 UTC
Message-ID: <7vty9ijs1i.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1313438699-9926-1-git-send-email-frederic.heitzmann@gmail.com>

Frédéric Heitzmann  <frederic.heitzmann@gmail.com> writes:

> The 'pre-svn-dcommit' hook is called before 'git svn dcommit', which aborts
> if return value is not zero. The only parameter given to the hook is the
> reference given to 'git svn dcommit'. If no paramter was used, hook gets HEAD
> as its only parameter.

It appears that this is in the same spirit as the pre-commit hook used in "git commit", so it may not hurt but I do not know if having a separate hook is the optimal approach to achieve what it wants to do.

I notice that git-svn users have been happily using the subsystem without need for any hook (not just pre-commit). Does "git svn" need an equivalent of pre-commit hook? If so, does it need equivalents to other hooks as well? I am not suggesting you to add support for a boatload of other hooks in this patch---I am trying to see if this is really a necessary change to begin with.

Eric, do you want this one?

Show 13 quoted lines

> diff --git a/git-svn.perl b/git-svn.perl
> index 89f83fd..a537858 100755
> --- a/git-svn.perl
> +++ b/git-svn.perl
> @@ -396,6 +396,25 @@ sub init_subdir {
>  	$_repository = Git->repository(Repository => $ENV{GIT_DIR});
>  }
>  
> +sub pre_svn_dcommit_hook {
> +	my $head = shift;
> +
> +	my $hook = "$ENV{GIT_DIR}/hooks/pre-svn-dcommit";
> +	return 0 if ! -e $hook || ! -x $hook;

Why force two stat(), instead of just "if ! -x $hook"? Doesn't it respond to a non-existing $hook with "there is nothing executable there" just fine?

Show 12 quoted lines

> +	system($hook, $head);
> +	if ($? == -1) {
> +		print "[pre_svn_dcommit_hook] failed to execute $hook: $!\n";
> +		return 1;
> +	} elsif ($? & 127) {
> +		printf "[pre_svn_dcommit_hook] child died with signal %d, %s coredump\n",
> +		($? & 127),  ($? & 128) ? 'with' : 'without';
> +		return 1;
> +	} else {
> +		return $? >> 8;
> +	}
> +}

Should these messages go to the standard output?

Show 12 quoted lines

>  sub cmd_clone {
>  	my ($url, $path) = @_;
>  	if (!defined $path &&
> @@ -505,6 +524,8 @@ sub cmd_dcommit {
>  		. "or stash them with `git stash'.\n";
>  	$head ||= 'HEAD';
>  
> +	return if pre_svn_dcommit_hook($head);
> +
>  	my $old_head;
>  	if ($head ne 'HEAD') {
>  		$old_head = eval {