builtin/clone: create the refdb with the correct object format

We're currently creating the reference database with a potentially
incorrect object format when the remote repository's object format is
different from the local default object format. This works just fine for
now because the files backend never records the object format anywhere.
But this logic will fail with any new reference backend that encodes
this information in some form either on-disk or in-memory.

The preceding commits have reshuffled code in git-clone(1) so that there
is no code path that will access the reference database before we have
detected the remote's object format. With these refactorings we can now
defer initialization of the reference database until after we have
learned the remote's object format and thus initialize it with the
correct format from the get-go.

These refactorings are required to make git-clone(1) work with the
upcoming reftable backend when cloning repositories with the SHA256
object format.

This change breaks a test in "t5550-http-fetch-dumb.sh" when cloning an
empty repository with `GIT_TEST_DEFAULT_HASH=sha256`. The test expects
the resulting hash format of the empty cloned repository to match the
default hash, but now we always end up with a sha1 repository. The
problem is that for dumb HTTP fetches, we have no easy way to figure out
the remote's hash function except for deriving it based on the hash
length of refs in `info/refs`. But as the remote repository is empty we
cannot rely on this detection mechanism.

Before the change in this commit we already initialized the repository
with the default hash function and then left it as-is. With this patch
we always use the hash function detected via the remote, where we fall
back to "sha1" in case we cannot detect it.

Neither the old nor the new behaviour are correct as we second-guess the
remote hash function in both cases. But given that this is a rather
unlikely edge case (we use the dumb HTTP protocol, the remote repository
uses SHA256 and the remote repository is empty), let's simply adapt the
test to assert the new behaviour. If we want to properly address this
edge case in the future we will have to extend the dumb HTTP protocol so
that we can properly detect the hash function for empty repositories.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
4 files changed
tree: 44a8582d55897b2758c46d5ba42d4e25dcddf35d
  1. .github/
  2. block-sha1/
  3. builtin/
  4. ci/
  5. compat/
  6. contrib/
  7. Documentation/
  8. ewah/
  9. git-gui/
  10. gitk-git/
  11. gitweb/
  12. mergetools/
  13. negotiator/
  14. oss-fuzz/
  15. perl/
  16. po/
  17. refs/
  18. reftable/
  19. sha1/
  20. sha1dc/
  21. sha256/
  22. t/
  23. templates/
  24. trace2/
  25. xdiff/
  26. .cirrus.yml
  27. .clang-format
  28. .editorconfig
  29. .gitattributes
  30. .gitignore
  31. .gitmodules
  32. .mailmap
  33. .tsan-suppressions
  34. abspath.c
  35. abspath.h
  36. aclocal.m4
  37. add-interactive.c
  38. add-interactive.h
  39. add-patch.c
  40. advice.c
  41. advice.h
  42. alias.c
  43. alias.h
  44. alloc.c
  45. alloc.h
  46. apply.c
  47. apply.h
  48. archive-tar.c
  49. archive-zip.c
  50. archive.c
  51. archive.h
  52. attr.c
  53. attr.h
  54. banned.h
  55. base85.c
  56. base85.h
  57. bisect.c
  58. bisect.h
  59. blame.c
  60. blame.h
  61. blob.c
  62. blob.h
  63. bloom.c
  64. bloom.h
  65. branch.c
  66. branch.h
  67. builtin.h
  68. bulk-checkin.c
  69. bulk-checkin.h
  70. bundle-uri.c
  71. bundle-uri.h
  72. bundle.c
  73. bundle.h
  74. cache-tree.c
  75. cache-tree.h
  76. cbtree.c
  77. cbtree.h
  78. chdir-notify.c
  79. chdir-notify.h
  80. check-builtins.sh
  81. checkout.c
  82. checkout.h
  83. chunk-format.c
  84. chunk-format.h
  85. CODE_OF_CONDUCT.md
  86. color.c
  87. color.h
  88. column.c
  89. column.h
  90. combine-diff.c
  91. command-list.txt
  92. commit-graph.c
  93. commit-graph.h
  94. commit-reach.c
  95. commit-reach.h
  96. commit-slab-decl.h
  97. commit-slab-impl.h
  98. commit-slab.h
  99. commit.c
  100. commit.h
  101. common-main.c
  102. config.c
  103. config.h
  104. config.mak.dev
  105. config.mak.in
  106. config.mak.uname
  107. configure.ac
  108. connect.c
  109. connect.h
  110. connected.c
  111. connected.h
  112. convert.c
  113. convert.h
  114. copy.c
  115. copy.h
  116. COPYING
  117. credential.c
  118. credential.h
  119. csum-file.c
  120. csum-file.h
  121. ctype.c
  122. daemon.c
  123. date.c
  124. date.h
  125. decorate.c
  126. decorate.h
  127. delta-islands.c
  128. delta-islands.h
  129. delta.h
  130. detect-compiler
  131. diagnose.c
  132. diagnose.h
  133. diff-delta.c
  134. diff-lib.c
  135. diff-merges.c
  136. diff-merges.h
  137. diff-no-index.c
  138. diff.c
  139. diff.h
  140. diffcore-break.c
  141. diffcore-delta.c
  142. diffcore-order.c
  143. diffcore-pickaxe.c
  144. diffcore-rename.c
  145. diffcore-rotate.c
  146. diffcore.h
  147. dir-iterator.c
  148. dir-iterator.h
  149. dir.c
  150. dir.h
  151. editor.c
  152. editor.h
  153. entry.c
  154. entry.h
  155. environment.c
  156. environment.h
  157. exec-cmd.c
  158. exec-cmd.h
  159. fetch-negotiator.c
  160. fetch-negotiator.h
  161. fetch-pack.c
  162. fetch-pack.h
  163. fmt-merge-msg.c
  164. fmt-merge-msg.h
  165. fsck.c
  166. fsck.h
  167. fsmonitor--daemon.h
  168. fsmonitor-ipc.c
  169. fsmonitor-ipc.h
  170. fsmonitor-ll.h
  171. fsmonitor-path-utils.h
  172. fsmonitor-settings.c
  173. fsmonitor-settings.h
  174. fsmonitor.c
  175. fsmonitor.h
  176. generate-cmdlist.sh
  177. generate-configlist.sh
  178. generate-hooklist.sh
  179. gettext.c
  180. gettext.h
  181. git-archimport.perl
  182. git-compat-util.h
  183. git-curl-compat.h
  184. git-cvsexportcommit.perl
  185. git-cvsimport.perl
  186. git-cvsserver.perl
  187. git-difftool--helper.sh
  188. git-filter-branch.sh
  189. git-instaweb.sh
  190. git-merge-octopus.sh
  191. git-merge-one-file.sh
  192. git-merge-resolve.sh
  193. git-mergetool--lib.sh
  194. git-mergetool.sh
  195. git-p4.py
  196. git-quiltimport.sh
  197. git-request-pull.sh
  198. git-send-email.perl
  199. git-sh-i18n.sh
  200. git-sh-setup.sh
  201. git-submodule.sh
  202. git-svn.perl
  203. GIT-VERSION-GEN
  204. git-web--browse.sh
  205. git-zlib.c
  206. git-zlib.h
  207. git.c
  208. git.rc
  209. gpg-interface.c
  210. gpg-interface.h
  211. graph.c
  212. graph.h
  213. grep.c
  214. grep.h
  215. hash-ll.h
  216. hash-lookup.c
  217. hash-lookup.h
  218. hash.h
  219. hashmap.c
  220. hashmap.h
  221. help.c
  222. help.h
  223. hex-ll.c
  224. hex-ll.h
  225. hex.c
  226. hex.h
  227. hook.c
  228. hook.h
  229. http-backend.c
  230. http-fetch.c
  231. http-push.c
  232. http-walker.c
  233. http.c
  234. http.h
  235. ident.c
  236. ident.h
  237. imap-send.c
  238. INSTALL
  239. iterator.h
  240. json-writer.c
  241. json-writer.h
  242. khash.h
  243. kwset.c
  244. kwset.h
  245. levenshtein.c
  246. levenshtein.h
  247. LGPL-2.1
  248. line-log.c
  249. line-log.h
  250. line-range.c
  251. line-range.h
  252. linear-assignment.c
  253. linear-assignment.h
  254. list-objects-filter-options.c
  255. list-objects-filter-options.h
  256. list-objects-filter.c
  257. list-objects-filter.h
  258. list-objects.c
  259. list-objects.h
  260. list.h
  261. lockfile.c
  262. lockfile.h
  263. log-tree.c
  264. log-tree.h
  265. ls-refs.c
  266. ls-refs.h
  267. mailinfo.c
  268. mailinfo.h
  269. mailmap.c
  270. mailmap.h
  271. Makefile
  272. match-trees.c
  273. match-trees.h
  274. mem-pool.c
  275. mem-pool.h
  276. merge-blobs.c
  277. merge-blobs.h
  278. merge-ll.c
  279. merge-ll.h
  280. merge-ort-wrappers.c
  281. merge-ort-wrappers.h
  282. merge-ort.c
  283. merge-ort.h
  284. merge-recursive.c
  285. merge-recursive.h
  286. merge.c
  287. merge.h
  288. mergesort.h
  289. midx.c
  290. midx.h
  291. name-hash.c
  292. name-hash.h
  293. notes-cache.c
  294. notes-cache.h
  295. notes-merge.c
  296. notes-merge.h
  297. notes-utils.c
  298. notes-utils.h
  299. notes.c
  300. notes.h
  301. object-file.c
  302. object-file.h
  303. object-name.c
  304. object-name.h
  305. object-store-ll.h
  306. object-store.h
  307. object.c
  308. object.h
  309. oid-array.c
  310. oid-array.h
  311. oidmap.c
  312. oidmap.h
  313. oidset.c
  314. oidset.h
  315. oidtree.c
  316. oidtree.h
  317. pack-bitmap-write.c
  318. pack-bitmap.c
  319. pack-bitmap.h
  320. pack-check.c
  321. pack-mtimes.c
  322. pack-mtimes.h
  323. pack-objects.c
  324. pack-objects.h
  325. pack-revindex.c
  326. pack-revindex.h
  327. pack-write.c
  328. pack.h
  329. packfile.c
  330. packfile.h
  331. pager.c
  332. pager.h
  333. parallel-checkout.c
  334. parallel-checkout.h
  335. parse-options-cb.c
  336. parse-options.c
  337. parse-options.h
  338. parse.c
  339. parse.h
  340. patch-delta.c
  341. patch-ids.c
  342. patch-ids.h
  343. path.c
  344. path.h
  345. pathspec.c
  346. pathspec.h
  347. pkt-line.c
  348. pkt-line.h
  349. preload-index.c
  350. preload-index.h
  351. pretty.c
  352. pretty.h
  353. prio-queue.c
  354. prio-queue.h
  355. progress.c
  356. progress.h
  357. promisor-remote.c
  358. promisor-remote.h
  359. prompt.c
  360. prompt.h
  361. protocol-caps.c
  362. protocol-caps.h
  363. protocol.c
  364. protocol.h
  365. prune-packed.c
  366. prune-packed.h
  367. quote.c
  368. quote.h
  369. range-diff.c
  370. range-diff.h
  371. reachable.c
  372. reachable.h
  373. read-cache-ll.h
  374. read-cache.c
  375. read-cache.h
  376. README.md
  377. rebase-interactive.c
  378. rebase-interactive.h
  379. rebase.c
  380. rebase.h
  381. ref-filter.c
  382. ref-filter.h
  383. reflog-walk.c
  384. reflog-walk.h
  385. reflog.c
  386. reflog.h
  387. refs.c
  388. refs.h
  389. refspec.c
  390. refspec.h
  391. remote-curl.c
  392. remote.c
  393. remote.h
  394. replace-object.c
  395. replace-object.h
  396. repo-settings.c
  397. repository.c
  398. repository.h
  399. rerere.c
  400. rerere.h
  401. reset.c
  402. reset.h
  403. resolve-undo.c
  404. resolve-undo.h
  405. revision.c
  406. revision.h
  407. run-command.c
  408. run-command.h
  409. sane-ctype.h
  410. scalar.c
  411. SECURITY.md
  412. send-pack.c
  413. send-pack.h
  414. sequencer.c
  415. sequencer.h
  416. serve.c
  417. serve.h
  418. server-info.c
  419. server-info.h
  420. setup.c
  421. setup.h
  422. sh-i18n--envsubst.c
  423. sha1dc_git.c
  424. sha1dc_git.h
  425. shallow.c
  426. shallow.h
  427. shared.mak
  428. shell.c
  429. shortlog.h
  430. sideband.c
  431. sideband.h
  432. sigchain.c
  433. sigchain.h
  434. simple-ipc.h
  435. sparse-index.c
  436. sparse-index.h
  437. split-index.c
  438. split-index.h
  439. stable-qsort.c
  440. statinfo.c
  441. statinfo.h
  442. strbuf.c
  443. strbuf.h
  444. streaming.c
  445. streaming.h
  446. string-list.c
  447. string-list.h
  448. strmap.c
  449. strmap.h
  450. strvec.c
  451. strvec.h
  452. sub-process.c
  453. sub-process.h
  454. submodule-config.c
  455. submodule-config.h
  456. submodule.c
  457. submodule.h
  458. symlinks.c
  459. symlinks.h
  460. tag.c
  461. tag.h
  462. tar.h
  463. tempfile.c
  464. tempfile.h
  465. thread-utils.c
  466. thread-utils.h
  467. tmp-objdir.c
  468. tmp-objdir.h
  469. trace.c
  470. trace.h
  471. trace2.c
  472. trace2.h
  473. trailer.c
  474. trailer.h
  475. transport-helper.c
  476. transport-internal.h
  477. transport.c
  478. transport.h
  479. tree-diff.c
  480. tree-walk.c
  481. tree-walk.h
  482. tree.c
  483. tree.h
  484. unicode-width.h
  485. unimplemented.sh
  486. unix-socket.c
  487. unix-socket.h
  488. unix-stream-server.c
  489. unix-stream-server.h
  490. unpack-trees.c
  491. unpack-trees.h
  492. upload-pack.c
  493. upload-pack.h
  494. url.c
  495. url.h
  496. urlmatch.c
  497. urlmatch.h
  498. usage.c
  499. userdiff.c
  500. userdiff.h
  501. utf8.c
  502. utf8.h
  503. varint.c
  504. varint.h
  505. version.c
  506. version.h
  507. versioncmp.c
  508. versioncmp.h
  509. walker.c
  510. walker.h
  511. wildmatch.c
  512. wildmatch.h
  513. worktree.c
  514. worktree.h
  515. wrap-for-bin.sh
  516. wrapper.c
  517. wrapper.h
  518. write-or-die.c
  519. write-or-die.h
  520. ws.c
  521. ws.h
  522. wt-status.c
  523. wt-status.h
  524. xdiff-interface.c
  525. xdiff-interface.h
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 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