gb_maint::add_gitblog_submodule PHP Method

    static function add_gitblog_submodule()
    {
        # Add gitblog submodule
        $roundtrip_temp = false;
        $dotgitmodules = gb::$dir . '/.gitmodules';
        $did_have_dotgitmodules = is_file($dotgitmodules);
        $added = array();
        $origin_url = 'git://github.com/rsms/gitblog.git';
        # first, find the origin url if any
        $broken_gitblog_repo = false;
        if (is_dir(gb::$dir . '/.git')) {
            try {
                gb::log('deducing remote.origin.url for existing gitblog');
                $s = trim(git::exec('config remote.origin.url', null, gb::$dir . '/.git', gb::$dir));
                if ($s) {
                    $origin_url = $s;
                }
            } catch (GitError $e) {
                gb::log(LOG_WARNING, 'failed to read config remote.origin.url: %s', $e->getMessage());
                $broken_gitblog_repo = true;
            }
        }
        # if gitblog is not a repo or broken, rename existing and clone a fresh copy from upstream
        if ($broken_gitblog_repo) {
            $stash_dir = gb::$dir . '.old';
            $i = 1;
            while (file_exists($stash_dir)) {
                $stash_dir = gb::$dir . '.old' . $i++;
            }
            gb::log('moving broken gitblog %s to %s', gb::$dir, $stash_dir);
            if (!rename(gb::$dir, $stash_dir)) {
                # Note: This is tricky. If we get here, it probably means we are unable to
                # write in dirname(gb::$dir) and gb::$site_dir which we will try to do
                # further down, where we clone a new copy, which will most likely fail
                # because we can not create a new directory called "gitblog" due to lack of
                # priveleges.
                #
                # Now, one solution would be to:
                #
                #   git clone origin /tmp/xy
                #   mkdir ./gitblog/old
                #   mv ./gitblog/(?!old)+ ./gitblog/old/
                #   mv /tmp/xy/* ./gitblog/
                #   rm -rf ./gitblog/old
                #
                # But as this is a very thin use case, almost vanishingly small since
                # the gitblog itself can not function w/o write rights, we die hard:
                gb::log(LOG_CRIT, 'unable to replace gitblog with gitblog submodule (mv %s %s) -- directory not writable? Aborting.', gb::$dir, $stash_dir);
                exit;
            }
        }
        try {
            # remove "/gitblog" ignore from .gitignore
            if (self::gitignore_sub('/(?:\\r?\\n)\\/gitblog([\\t\\s \\r\\n]+|^)/m', '$1')) {
                $added[] = git::add('.gitignore');
            }
            # register (and clone if needed) the gitblog submodule. This might take some time.
            try {
                git::exec('submodule --quiet add -b ' . escapeshellarg(self::$branch) . ' -- ' . escapeshellarg($origin_url) . ' gitblog');
                # add gitblog
                $added[] = git::add('gitblog');
            } catch (GitError $e) {
                if (strpos($e->getMessage(), 'already exists in the index') === false) {
                    throw $e;
                }
            }
            # move back old shallow gitblog dir
            if ($roundtrip_temp) {
                $old_dst = gb::$dir . '/gitblog.old';
                gb::log('moving %s to %s', $roundtrip_temp, $old_dst);
                if (!@rename($roundtrip_temp, $old_dst)) {
                    gb::log(LOG_ERR, 'failed to move back %s to %s', $roundtrip_temp, $old_dst);
                }
                # we want to explicitly checkout the branch we requested
                git::exec('checkout ' . escapeshellarg(self::$branch), null, gb::$dir . '/.git', gb::$dir);
            }
        } catch (Exception $e) {
            # move back gitblog dir
            if ($roundtrip_temp) {
                gb::log('moving %s to %s', $roundtrip_temp, gb::$dir);
                if (!@rename($roundtrip_temp, gb::$dir)) {
                    gb::log(LOG_ERR, 'failed to move back %s to %s', $roundtrip_temp, gb::$dir);
                }
            }
            # forward exception
            throw $e;
        }
        # if .submodules did not exist when we started, track it
        if (!$did_have_dotgitmodules && is_file(gb::$site_dir . '/.gitmodules')) {
            $added[] = git::add('.gitmodules');
        }
        # commit any modifications
        if ($added) {
            try {
                git::commit('added ' . implode(', ', $added), GBUser::findAdmin()->gitAuthor(), $added);
            } catch (GitError $e) {
                if (strpos($e->getMessage(), 'no changes added to commit') === false) {
                    throw $e;
                }
            }
        }
    }

 static function _000103($from, $to)
 {
     gb_maint::add_gitblog_submodule();
 }