When we parse a config file, we set up the global "cf"
variable as a pointer to a "struct config_source" describing
the file we are parsing. This is used for error messages, as
well as for lookup functions like current_config_name().
The "cf" variable is NULL in two cases:
1. When we are parsing command-line config, in which case
there is no source file.
2. When we are not parsing any config at all.
Callers like current_config_name() must assume we are in
case 1 if they see a NULL "cf". However, this means that if
they are accidentally used outside of a config parsing
callback, they will quietly return a bogus answer.
This might seem like an unlikely accident (why would you ask
for the current config file if you are not parsing config?),
but it's actually an easy mistake to make due to the
configset caching. git_config() serves the answers from a
configset cache, and any calls to current_config_name() will
claim that we are parsing command-line config, no matter
what the original source.
So let's distinguish these cases by having the command-line
config parser set up a config_source with a NULL name (which
callers already handle properly). We can use this to catch
programming errors in some cases, and to give better
messages to the user in others.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git - fast, scalable, distributed revision control system
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 version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.
Please read the file INSTALL for installation instructions.
Many Git online resources are accessible from http://git-scm.com/ including full documentation and Git related tools.
See Documentation/gittutorial.txt to get started, then see Documentation/giteveryday.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).
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://news.gmane.org/gmane.comp.version-control.git/, http://marc.info/?l=git and other archival sites.
The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.
The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (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