The comment in parse_commit_date() claims that parse_timestamp() will not walk past the end of the buffer we've been given, since it will hit the newline at "eol" and stop. This is usually true, when dateptr contains actual numbers to parse. But with a line like: committer name <email> \n with just whitespace, and no numbers, parse_timestamp() will consume that newline as part of the leading whitespace, and we may walk past our "tail" pointer (which itself is set from the "size" parameter passed in to parse_commit_buffer()). In practice this can't cause us to walk off the end of an array, because we always add an extra NUL byte to the end of objects we load from disk (as a defense against exactly this kind of bug). However, you can see the behavior in action when "committer" is the final header (which it usually is, unless there's an encoding) and the subject line can be parsed as an integer. We walk right past the newline on the committer line, as well as the "\n\n" separator, and mistake the subject for the timestamp. We can solve this by trimming the whitespace ourselves, making sure that it has some non-whitespace to parse. Note that we need to be a bit careful about the definition of "whitespace" here, as our isspace() doesn't match exotic characters like vertical tab or formfeed. We can work around that by checking for an actual number (see the in-code comment). This is slightly more restrictive than the current code, but in practice the results are either the same (we reject "foo" as "0", but so would parse_timestamp()) or extremely unlikely even for broken commits (parse_timestamp() would allow "\v123" as "123", but we'll now make it "0"). I did also allow "-" here, which may be controversial, as we don't currently support negative timestamps. My reasoning was two-fold. One, the design of parse_timestamp() is such that we should be able to easily switch it to handling signed values, and this otherwise creates a hard-to-find gotcha that anybody doing that work would get tripped up on. And two, the status quo is that we currently parse them, though the result of course ends up as a very large unsigned value (which is likely to just get clamped to "0" for display anyway, since our date routines can't handle it). The new test checks the commit parser (via "--until") for both vanilla spaces and the vertical-tab case. I also added a test to check these against the pretty-print formatter, which uses split_ident_line(). It's not subject to the same bug, because it already insists that there be one or more digits in the timestamp. Helped-by: Phillip Wood <phillip.wood123@gmail.com> 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).
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 and Documentation/CodingGuidelines).
Those wishing to help with error message, usage and informational message
string translations (localization l10) should see po/README.md
(a po file is a Portable Object file that holds the translations).
To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org (not the Git list). The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.
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