The process for guessing an archive output format based on
the filename is something like this:
a. parse --output in cmd_archive; check the filename
against a static set of mapping heuristics (right now
it just matches ".zip" for zip files).
b. if found, stick a fake "--format=zip" at the beginning
of the arguments list (if the user did specify a
--format manually, the later option will override our
fake one)
c. if it's a remote call, ship the arguments to the remote
(including the fake), which will call write_archive on
their end
d. if it's local, ship the arguments to write_archive
locally
There are two problems:
1. The set of mappings is static and at too high a level.
The write_archive level is going to check config for
user-defined formats, some of which will specify
extensions. We need to delay lookup until those are
parsed, so we can match against them.
2. For a remote archive call, our set of mappings (or
formats) may not match the remote side's. This is OK in
practice right now, because all versions of git
understand "zip" and "tar". But as new formats are
added, there is going to be a mismatch between what the
client can do and what the remote server can do.
To fix (1), this patch refactors the location guessing to
happen at the write_archive level, instead of the
cmd_archive level. So instead of sticking a fake --format
field in the argv list, we actually pass a "name hint" down
the callchain; this hint is used at the appropriate time to
guess the format (if one hasn't been given already).
This patch leaves (2) unfixed. The name_hint is converted to
a "--format" option as before, and passed to the remote.
This means the local side's idea of how extensions map to
formats will take precedence.
Another option would be to pass the name hint to the remote
side and let the remote choose. This isn't a good idea for
two reasons:
1. There's no room in the protocol for passing that
information. We can pass a new argument, but older
versions of git on the server will choke on it.
2. Letting the remote side decide creates a silent
inconsistency in user experience. Consider the case
that the locally installed git knows about the "tar.gz"
format, but a remote server doesn't.
Running "git archive -o foo.tar.gz" will use the tar.gz
format. If we use --remote, and the local side chooses
the format, then we send "--format=tar.gz" to the
remote, which will complain about the unknown format.
But if we let the remote side choose the format, then
it will realize that it doesn't know about "tar.gz" and
output uncompressed tar without even issuing a warning.
Signed-off-by: Jeff King <peff@peff.net>
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. 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.