Merge branch 'tg/stash-untracked-with-pathspec-fix'

"git stash push -u -- <pathspec>" gave an unnecessary and confusing error message when there was no tracked files that match the <pathspec>, which has been fixed. * tg/stash-untracked-with-pathspec-fix: stash: drop superfluos pathspec parameter stash push -u: don't create empty stash stash push: avoid printing errors stash: fix nonsense pipeline