Re: [PATCH] Calculate $commitsha1 in update() only when needed

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

Pavel Roskin <proski@gnu.org> writes:

> diff --git a/git-cvsserver.perl b/git-cvsserver.perl
> index ecded3b..409b301 100755
> --- a/git-cvsserver.perl
> +++ b/git-cvsserver.perl
> @@ -2427,9 +2427,6 @@ sub update
>      # first lets get the commit list
>      $ENV{GIT_DIR} = $self->{git_path};
>  
> -    my $commitsha1 = `git rev-parse $self->{module}`;
> -    chomp $commitsha1;
> -
>      my $commitinfo = `git cat-file commit $self->{module} 2>&1`;
>      unless ( $commitinfo =~ /tree\s+[a-zA-Z0-9]{40}/ )
>      {

Hmm.  The first rev-parse could be squelched with 2>/dev/null and then
you can check if it does not match [a-f0-9]{40} and die early before
running "cat-file commit", can't you?

Also the regexp to check "tree" object name above seems quite wrong ;-)
If the purpose of this check is to make sure if the ref points at a
commit object, perhaps...

	my $commitsha1 = `git rev-parse --verify $self->{module}^0 2>&1`;
	chomp($commitsha1);
        if ($commitsha1 !~ /^[0-9a-f]{40}$/) {
        	die "no such module $self->{module}";
	}

Then the other hunk below would become unnecessary, I think.

> @@ -2440,8 +2437,13 @@ sub update
>      my $git_log;
>      my $lastcommit = $self->_get_prop("last_commit");
>  
> -    if (defined $lastcommit && $lastcommit eq $commitsha1) { # up-to-date
> -         return 1;
> +    if (defined $lastcommit) {
> +        my $commitsha1 = `git rev-parse $self->{module}`;
> +        chomp $commitsha1;
> +
> +        if ($lastcommit eq $commitsha1) { # up-to-date
> +            return 1;
> +        }
>      }
>  
>      # Start exclusive lock here...