We've never intended to support diff's --output option in format-patch.
And until baa4adc66a (parse-options: disable option abbreviation with
PARSE_OPT_KEEP_UNKNOWN, 2019-01-27), it was impossible to trigger. We
first parse the format-patch options before handing the remainder off to
setup_revisions(). Before that commit, we'd accept "--output=foo" as an
abbreviation for "--output-directory=foo". But afterwards, we don't
check abbreviations, and --output gets passed to the diff code.
This results in nonsense behavior and bugs. The diff code will have
opened a filehandle at rev.diffopt.file, but we'll overwrite that with
our own handles that we open for each individual patch file. So the
--output file will always just be empty. But worse, the diff code also
sets rev.diffopt.close_file, so log_tree_commit() will close the
filehandle itself. And then the main loop in cmd_format_patch() will try
to close it again, resulting in a double-free.
The simplest solution would be to just disallow --output with
format-patch, as nobody ever intended it to work. However, we have
accidentally documented it (because format-patch includes diff-options).
And it does work with "git log", which writes the whole output to the
specified file. It's easy enough to make that work for format-patch,
too: it's really the same as --stdout, but pointed at a specific file.
We can detect the use of the --output option by the "close_file" flag
(note that we can't use rev.diffopt.file, since the diff setup will
otherwise set it to stdout). So we just need to unset that flag, but
don't have to do anything else. Our situation is otherwise exactly like
--stdout (note that we don't fclose() the file, but nor does the stdout
case; exiting the program takes care of that for us).
Reported-by: Johannes Postler <johannes.postler@txture.io>
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 https://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).
Issues which are security relevant should be disclosed privately to
the Git Security mailing list git-security@googlegroups.com.
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
