src/PEAR/Downloader/Package.php
function _fromFile(&$param)
    {
        $saveparam = $param;
        if (is_string($param)) {
            if (!@file_exists($param)) {
                $test = explode('#', $param);
                $group = array_pop($test);
                if (@file_exists(implode('#', $test))) {
                    $this->setGroup($group);
                    $param = implode('#', $test);
                    $this->_explicitGroup = true;
                }
            }

            if (@is_file($param)) {
                $this->_type = 'local';
                $options = $this->_downloader->getOptions();
                $pkg = &$this->getPackagefileObject($this->_config, $this->_downloader->_debug);
                PEAR::pushErrorHandling(PEAR_ERROR_RETURN);
                $pf = &$pkg->fromAnyFile($param, PEAR_VALIDATE_INSTALLING);
                PEAR::popErrorHandling();
                if (PEAR::isError($pf)) {
                    $this->_valid = false;
                    $param = $saveparam;
                    return $pf;
                }
                $this->_packagefile = &$pf;
                if (!$this->getGroup()) {
                    $this->setGroup('default'); // install the default dependency group
                }
                return $this->_valid = true;
            }
        }
        $param = $saveparam;
        return $this->_valid = false;
    }
function _fromFile(&$param)
    {
        $saveparam = $param;
        if (is_string($param)) {
            if (!@file_exists($param)) {
                $test = explode('#', $param);
                $group = array_pop($test);
                if (@file_exists(implode('#', $test))) {
                    $this->setGroup($group);
                    $param = implode('#', $test);
                    $this->_explicitGroup = true;
                }
            }

            if (@is_file($param)) {
                $this->_type = 'local';
                $options = $this->_downloader->getOptions();
                $pkg = &$this->getPackagefileObject($this->_config, $this->_downloader->_debug);
                PEAR::pushErrorHandling(PEAR_ERROR_RETURN);
                $pf = &$pkg->fromAnyFile($param, PEAR_VALIDATE_INSTALLING);
                PEAR::popErrorHandling();
                if (PEAR::isError($pf)) {
                    $this->_valid = false;
                    $param = $saveparam;
                    return $pf;
                }
                $this->_packagefile = &$pf;
                if (!$this->getGroup()) {
                    $this->setGroup('default'); // install the default dependency group
                }
                return $this->_valid = true;
            }
        }
        $param = $saveparam;
        return $this->_valid = false;
    }
This will retrieve from a local file if possible, and parse out
a group name as well.  The original parameter will be modified to reflect this.
@param string|array can be a parsed package name as well
@access private