4e76832984
It's possible for content currently found in one file to
have originated in two separate files, each of which may
have been modified in some single older commit. The
--porcelain output generates an incorrect "previous" header
in this case, whereas --line-porcelain gets it right. The
problem is that the porcelain output tries to omit repeated
details of commits, and treats "previous" as a property of
the commit, when it is really a property of the blamed block
of lines.
Let's look at an example. In a case like this, you might see
this output from --line-porcelain:
SOME_SHA1 1 1 1
author ...
committer ...
previous SOME_SHA1^ file_one
filename file_one
...some line content...
SOME_SHA1 2 1 1
author ...
committer ...
previous SOME_SHA1^ file_two
filename file_two
...some different content....
The "filename" fields tell us that the two lines are from
two different files. But notice that the filename also
appears in the "previous" field, which tells us where to
start a re-blame. The second content line never appeared in
file_one at all, so we would obviously need to re-blame from
file_two (or possibly even some other file, if had just been
renamed to file_two in SOME_SHA1).
So far so good. Now here's what --porcelain looks like:
SOME_SHA1 1 1 1
author ...
committer ...
previous SOME_SHA1^ file_one
filename file_one
...some line content...
SOME_SHA1 2 1 1
filename file_two
...some different content....
We've dropped the author and committer fields from the
second line, as they would just be repeats. But we can't
omit "filename", because it depends on the actual block of
blamed lines, not just the commit. This is handled by
emit_porcelain_details(), which will show the filename
either if it is the first mention of the commit _or_ if the
commit has multiple paths in it.
But we don't give "previous" the same handling. It's written
inside emit_one_suspect_detail(), which bails early if we've
already seen that commit. And so the output above is wrong;
a reader would assume that the correct place to re-blame
line two is from file_one, but that's obviously nonsense.
Let's treat "previous" the same as "filename", and show it
fresh whenever we know we are in a confusing case like this.
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-.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