Re: [PATCH 3/9] gitweb: Add option to force version match

> This adds $git_versions_must_match variable, which is set to true,
> checks that we are running on the same version of git that we
> shipped with, and if not throw '500 Internal Server Error' error.
> What is checked is the version of gitweb (embedded in building
> gitweb.cgi), against version of runtime git binary used.
> 
> Gitweb can usually run with a mismatched git install.  This is more
> here to give an obvious warning as to whats going on vs. silently
> failing.
> 
> By default this feature is turned on.

>  gitweb/README      |    3 +++
>  gitweb/gitweb.perl |   23 +++++++++++++++++++++++
>  2 files changed, 26 insertions(+), 0 deletions(-)
> 
> diff --git a/gitweb/README b/gitweb/README
> index 6c2c8e1..03151d2 100644
> --- a/gitweb/README
> +++ b/gitweb/README
> @@ -233,6 +233,9 @@ not include variables usually directly set during build):
>     If server load exceed this value then return "503 Service Unavaliable" error.
>     Server load is taken to be 0 if gitweb cannot determine its value.  Set it to
>     undefined value to turn it off.  The default is 300.
> + * $git_versions_must_match
> +   If set, gitweb fails with 500 Internal Server Error if the version of gitweb
> +   doesn't match version of git binary.  The default is true.
>  
>  
>  Projects list file format
> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 8298de5..b41bc33 100755
> --- a/gitweb/gitweb.perl
> +++ b/gitweb/gitweb.perl
> @@ -221,6 +221,9 @@ our %avatar_size = (
>  	'double'  => 32
>  );
>  
> +# If it is true, exit if gitweb version and git binary version don't match
> +our $git_versions_must_match = 1;
> +
>  # Used to set the maximum load that we will still respond to gitweb queries.
>  # If server load exceed this value then return "503 server busy" error.
>  # If gitweb cannot determined server load, it is taken to be 0.
> @@ -587,6 +590,26 @@ if (defined $maxload && get_loadavg() > $maxload) {
>  our $git_version = qx("$GIT" --version) =~ m/git version (.*)$/ ? $1 : "unknown";
>  $number_of_git_cmds++;
>  
> +# Throw an error if git versions does not match, if $git_versions_must_match is true.
> +if ($git_versions_must_match &&
> +    $git_version ne $version) {
> +	my $admin_contact =
> +		defined $ENV{'SERVER_ADMIN'} ? ", $ENV{'SERVER_ADMIN'}," : '';
> +	my $err_msg = <<EOT;
> +<h1 align="center">*** Warning ***</h1>
> +<p>
> +This version of gitweb was compiled for <b>@{[esc_html($version)]}</b>,
> +however git version <b>@{[esc_html($git_version)]}</b> was found on server,
> +and administrator requested strict version checking.
> +</p>
> +<p>
> +Please contact the server administrator${admin_contact} to either configure
> +gitweb to allow mismatched versions, or update git or gitweb installation.
> +</p>
> +EOT
> +	die_error(500, 'Internal server error', $err_msg);
> +}
> +
>  $projects_list ||= $projectroot;
>  
>  # ======================================================================