/**
* Retrieve the latest tag from a branch.
*
* @param string $branch The branch name to retrieve the tag from.
*
* @return null|string Returns null when no tag has been found, the tag name otherwise.
*/
protected function getTagFromBranch($branch)
{
$git = new GitRepository($this->input->getArgument('git-dir'));
$tag = trim($git->describe()->tags()->always()->execute($branch));
$hash = trim($git->revParse()->short(false)->execute($branch));
return $hash !== $tag ? $tag : null;
}
