completion tests: add tests for the __git_refs() helper function
Check how __git_refs() lists refs in different scenarios, i.e.
- short and full refs,
- from a local or from a remote repository,
- remote specified via path, name or URL,
- with or without a repository specified on the command line,
- non-existing remote,
- unique remote branches for 'git checkout's tracking DWIMery,
- not in a git repository, and
- interesting combinations of the above.
Seven of these tests expect failure, mostly demonstrating bugs related
to listing refs from a remote repository:
- ignoring the repository specified on the command line (2 tests),
- listing refs from the wrong place when the name of a configured
remote happens to match a directory,
- listing only 'HEAD' but no short refs from a remote given as URL,
- listing 'HEAD' even from non-existing remotes (2 tests), and
- listing 'HEAD' when not in a repository.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>