verify_repository_format(): complain about new extensions in v0 repo

We made the mistake in the past of respecting extensions.* even when the
repository format version was set to 0. This is bad because forgetting
to bump the repository version means that older versions of Git (which
do not know about our extensions) won't complain. I.e., it's not a
problem in itself, but it means your repository is in a state which does
not give you the protection you think you're getting from older
versions.

For compatibility reasons, we are stuck with that decision for existing
extensions. However, we'd prefer not to extend the damage further. We
can do that by catching any newly-added extensions and complaining about
the repository format.

Note that this is a pretty heavy hammer: we'll refuse to work with the
repository at all. A lesser option would be to ignore (possibly with a
warning) any new extensions. But because of the way the extensions are
handled, that puts the burden on each new extension that is added to
remember to "undo" itself (because they are handled before we know
for sure whether we are in a v1 repo or not, since we don't insist on a
particular ordering of config entries).

So one option would be to rewrite that handling to record any new
extensions (and their values) during the config parse, and then only
after proceed to handle new ones only if we're in a v1 repository. But
I'm not sure if it's worth the trouble:

  - ignoring extensions is likely to end up with broken results anyway
    (e.g., ignoring a proposed objectformat extension means parsing any
    object data is likely to encounter errors)

  - this is a sign that whatever tool wrote the extension field is
    broken. We may be better off notifying immediately and forcefully so
    that such tools don't even appear to work accidentally.

The only downside is that fixing the situation is a little tricky,
because programs like "git config" won't want to work with the
repository. But:

  git config --file=.git/config core.repositoryformatversion 1

should still suffice.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
3 files changed
tree: c3c5b7f3a29ee9c1c30c347e7a0be4c55eb928cd
  1. .github/
  2. block-sha1/
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  6. contrib/
  7. Documentation/
  8. ewah/
  9. git-gui/
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  165. gettext.c
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  170. git-compat-util.h
  171. git-cvsexportcommit.perl
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  182. git-p4.py
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  184. git-quiltimport.sh
  185. git-rebase--preserve-merges.sh
  186. git-request-pull.sh
  187. git-send-email.perl
  188. git-sh-i18n.sh
  189. git-sh-setup.sh
  190. git-submodule.sh
  191. git-svn.perl
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  269. notes-merge.c
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  276. object.c
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  278. oid-array.c
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  280. oidmap.c
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  282. oidset.c
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  284. pack-bitmap-write.c
  285. pack-bitmap.c
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  287. pack-check.c
  288. pack-objects.c
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  290. pack-revindex.c
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  292. pack-write.c
  293. pack.h
  294. packfile.c
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  296. pager.c
  297. parse-options-cb.c
  298. parse-options.c
  299. parse-options.h
  300. patch-delta.c
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  302. patch-ids.h
  303. path.c
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  305. pathspec.c
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  307. pkt-line.c
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  312. prio-queue.c
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  314. progress.c
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  318. prompt.c
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  320. protocol.c
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  322. prune-packed.c
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  324. quote.c
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  326. range-diff.c
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  328. reachable.c
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  330. read-cache.c
  331. README.md
  332. rebase-interactive.c
  333. rebase-interactive.h
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  335. rebase.h
  336. ref-filter.c
  337. ref-filter.h
  338. reflog-walk.c
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  340. refs.c
  341. refs.h
  342. refspec.c
  343. refspec.h
  344. remote-curl.c
  345. remote-testsvn.c
  346. remote.c
  347. remote.h
  348. replace-object.c
  349. replace-object.h
  350. repo-settings.c
  351. repository.c
  352. repository.h
  353. rerere.c
  354. rerere.h
  355. reset.c
  356. reset.h
  357. resolve-undo.c
  358. resolve-undo.h
  359. revision.c
  360. revision.h
  361. run-command.c
  362. run-command.h
  363. send-pack.c
  364. send-pack.h
  365. sequencer.c
  366. sequencer.h
  367. serve.c
  368. serve.h
  369. server-info.c
  370. setup.c
  371. sh-i18n--envsubst.c
  372. sha1-file.c
  373. sha1-lookup.c
  374. sha1-lookup.h
  375. sha1-name.c
  376. sha1dc_git.c
  377. sha1dc_git.h
  378. shallow.c
  379. shallow.h
  380. shell.c
  381. shortlog.h
  382. sideband.c
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  384. sigchain.c
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  386. split-index.c
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  388. stable-qsort.c
  389. strbuf.c
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  391. streaming.c
  392. streaming.h
  393. string-list.c
  394. string-list.h
  395. sub-process.c
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  397. submodule-config.c
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  399. submodule.c
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  401. symlinks.c
  402. tag.c
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  404. tar.h
  405. tempfile.c
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  407. thread-utils.c
  408. thread-utils.h
  409. tmp-objdir.c
  410. tmp-objdir.h
  411. trace.c
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  415. trailer.c
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  417. transport-helper.c
  418. transport-internal.h
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  421. tree-diff.c
  422. tree-walk.c
  423. tree-walk.h
  424. tree.c
  425. tree.h
  426. unicode-width.h
  427. unimplemented.sh
  428. unix-socket.c
  429. unix-socket.h
  430. unpack-trees.c
  431. unpack-trees.h
  432. upload-pack.c
  433. upload-pack.h
  434. url.c
  435. url.h
  436. urlmatch.c
  437. urlmatch.h
  438. usage.c
  439. userdiff.c
  440. userdiff.h
  441. utf8.c
  442. utf8.h
  443. varint.c
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  445. version.c
  446. version.h
  447. versioncmp.c
  448. walker.c
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  450. wildmatch.c
  451. wildmatch.h
  452. worktree.c
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  454. wrap-for-bin.sh
  455. wrapper.c
  456. write-or-die.c
  457. ws.c
  458. wt-status.c
  459. wt-status.h
  460. xdiff-interface.c
  461. xdiff-interface.h
  462. zlib.c
README.md

Build status

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). 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 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