The user can be presented with invalid completion results
when trying to complete a 'git checkout' command. This can happen
when using a branch name prefix that matches multiple remote branches.
For example, if available branches are:
master
remotes/GitHub/maint
remotes/GitHub/master
remotes/origin/maint
remotes/origin/master
When performing completion on 'git checkout ma' the user will be
given the choices:
maint
master
However, 'git checkout maint' will fail in this case, although
completion previously said 'maint' was valid. Furthermore, when
performing completion on 'git checkout mai', no choices will be
suggested. So, the user is first told that the branch name
'maint' is valid, but when trying to complete 'mai' into 'maint',
that completion is no longer valid.
The completion results should never propose 'maint' as a valid
branch name, since 'git checkout' will refuse it.
The reason for this bug is that the uniq program only
works with sorted input. The man page states
"uniq prints the unique lines in a sorted file".
When __git_refs uses the guess heuristic employed by checkout for
tracking branches it wants to consider remote branches but only if
the branch name is unique. To do that, it calls 'uniq -u'. However
the input given to 'uniq -u' is not sorted.
Therefore, in the above example, when dealing with 'git checkout ma',
"__git_refs '' 1" will find the following list:
master
maint
master
maint
master
which, when passed to 'uniq -u' will remain the same. Therefore
'maint' will be wrongly suggested as a valid option.
When dealing with 'git checkout mai', the list will be:
maint
maint
which happens to be sorted and will be emptied by 'uniq -u',
properly ignoring 'maint'.
A solution for preventing the completion script from suggesting
such invalid branch names is to first call 'sort' and then 'uniq -u'.
Signed-off-by: Marc Khouzam <marc.khouzam@gmail.com>
Reviewed-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
////////////////////////////////////////////////////////////////
GIT - the stupid content tracker
////////////////////////////////////////////////////////////////
"git" can mean anything, depending on your mood.
- random three-letter combination that is pronounceable, and not
actually used by any common UNIX command. The fact that it is a
mispronunciation of "get" may or may not be relevant.
- stupid. contemptible and despicable. simple. Take your pick from the
dictionary of slang.
- "global information tracker": you're in a good mood, and it actually
works for you. Angels sing, and a light suddenly fills the room.
- "goddamn idiotic truckload of sh*t": when it breaks
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations
and full access to internals.
Git is an Open Source project covered by the GNU General Public License.
It was originally written by Linus Torvalds with help of a group of
hackers around the net. It is currently maintained by Junio C Hamano.
Please read the file INSTALL for installation instructions.
See Documentation/gittutorial.txt to get started, then see
Documentation/everyday.txt for a useful minimum set of commands, and
Documentation/git-commandname.txt for documentation of each command.
If git has been correctly installed, then the tutorial can also be
read with "man gittutorial" or "git help tutorial", and the
documentation of each command with "man git-commandname" or "git help
commandname".
CVS users may also want to read Documentation/gitcvs-migration.txt
("man gitcvs-migration" or "git help cvs-migration" if git is
installed).
Many Git online resources are accessible from http://git-scm.com/
including full documentation and Git related tools.
The user discussion and development of Git take place on the Git
mailing list -- everyone is welcome to post bug reports, feature
requests, comments and patches to git@vger.kernel.org (read
Documentation/SubmittingPatches for instructions on patch submission).
To subscribe to the list, send an email with just "subscribe git" in
the body to majordomo@vger.kernel.org. The mailing list archives are
available at http://marc.theaimsgroup.com/?l=git and other archival
sites.
The messages titled "A note from the maintainer", "What's in
git.git (stable)" and "What's cooking in git.git (topics)" and
the discussion following them on the mailing list give a good
reference for project status, development direction and
remaining tasks.
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