git stash push -u deletes untracked files

Hi,

Using Git 2.16.3 on MacOS 10.13.3, running `git stash push --include-untracked` deletes the untracked files specified in its arguments and creates an empty stash commit.

In the example below, I create a repository with a single file and a single commit. Then I create two untracked files and push one of them to the stash. Although I get an error, an empty stash commit is generated and the specified file is deleted.

``` $ git init . && touch README && git commit -m "README" $ touch my-file my-other-file $ git status On branch master Untracked files: my-file my-other-file

nothing added to commit but untracked files present $ git stash push -u my-file Saved working directory and index state WIP on master: e89afc6 README fatal: pathspec 'my-file' did not match any files error: unrecognized input $ git status On branch master Untracked files: my-other-file

nothing added to commit but untracked files present $ git stash list stash@{0}: WIP on master: e89afc6 README $ git stash show $ $ ls README my-other-file ```

I tested this using git built from the latest commit on master at the time of writing (c2a499e6c31ed613a606ffdeb5bb74ab41e9a586) and got the same results. Could you please check it out?

Thank you,

Hosam Aly