alternates: accept double-quoted paths

We read lists of alternates from objects/info/alternates
files (delimited by newline), as well as from the
GIT_ALTERNATE_OBJECT_DIRECTORIES environment variable
(delimited by colon or semi-colon, depending on the
platform).

There's no mechanism for quoting the delimiters, so it's
impossible to specify an alternate path that contains a
colon in the environment, or one that contains a newline in
a file. We've lived with that restriction for ages because
both alternates and filenames with colons are relatively
rare, and it's only a problem when the two meet. But since
722ff7f87 (receive-pack: quarantine objects until
pre-receive accepts, 2016-10-03), which builds on the
alternates system, every push causes the receiver to set
GIT_ALTERNATE_OBJECT_DIRECTORIES internally.

It would be convenient to have some way to quote the
delimiter so that we can represent arbitrary paths.

The simplest thing would be an escape character before a
quoted delimiter (e.g., "\:" as a literal colon). But that
creates a backwards compatibility problem: any path which
uses that escape character is now broken, and we've just
shifted the problem. We could choose an unlikely escape
character (e.g., something from the non-printable ASCII
range), but that's awkward to use.

Instead, let's treat names as unquoted unless they begin
with a double-quote, in which case they are interpreted via
our usual C-stylke quoting rules. This also breaks
backwards-compatibility, but in a smaller way: it only
matters if your file has a double-quote as the very _first_
character in the path (whereas an escape character is a
problem anywhere in the path).  It's also consistent with
many other parts of git, which accept either a bare pathname
or a double-quoted one, and the sender can choose to quote
or not as required.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
3 files changed
tree: 6722d811a4918a54dc02d9ae57670d343dc3f93c
  1. block-sha1/
  2. builtin/
  3. ci/
  4. compat/
  5. contrib/
  6. Documentation/
  7. ewah/
  8. git-gui/
  9. gitk-git/
  10. gitweb/
  11. mergetools/
  12. perl/
  13. po/
  14. ppc/
  15. refs/
  16. t/
  17. templates/
  18. vcs-svn/
  19. xdiff/
  20. .gitattributes
  21. .gitignore
  22. .mailmap
  23. .travis.yml
  24. abspath.c
  25. aclocal.m4
  26. advice.c
  27. advice.h
  28. alias.c
  29. alloc.c
  30. apply.c
  31. apply.h
  32. archive-tar.c
  33. archive-zip.c
  34. archive.c
  35. archive.h
  36. argv-array.c
  37. argv-array.h
  38. attr.c
  39. attr.h
  40. base85.c
  41. bisect.c
  42. bisect.h
  43. blob.c
  44. blob.h
  45. branch.c
  46. branch.h
  47. builtin.h
  48. bulk-checkin.c
  49. bulk-checkin.h
  50. bundle.c
  51. bundle.h
  52. cache-tree.c
  53. cache-tree.h
  54. cache.h
  55. check-builtins.sh
  56. check-racy.c
  57. check_bindir
  58. color.c
  59. color.h
  60. column.c
  61. column.h
  62. combine-diff.c
  63. command-list.txt
  64. commit-slab.h
  65. commit.c
  66. commit.h
  67. common-main.c
  68. config.c
  69. config.mak.in
  70. config.mak.uname
  71. configure.ac
  72. connect.c
  73. connect.h
  74. connected.c
  75. connected.h
  76. convert.c
  77. convert.h
  78. copy.c
  79. COPYING
  80. credential-cache--daemon.c
  81. credential-cache.c
  82. credential-store.c
  83. credential.c
  84. credential.h
  85. csum-file.c
  86. csum-file.h
  87. ctype.c
  88. daemon.c
  89. date.c
  90. decorate.c
  91. decorate.h
  92. delta.h
  93. diff-delta.c
  94. diff-lib.c
  95. diff-no-index.c
  96. diff.c
  97. diff.h
  98. diffcore-break.c
  99. diffcore-delta.c
  100. diffcore-order.c
  101. diffcore-pickaxe.c
  102. diffcore-rename.c
  103. diffcore.h
  104. dir-iterator.c
  105. dir-iterator.h
  106. dir.c
  107. dir.h
  108. editor.c
  109. entry.c
  110. environment.c
  111. exec_cmd.c
  112. exec_cmd.h
  113. fast-import.c
  114. fetch-pack.c
  115. fetch-pack.h
  116. fmt-merge-msg.h
  117. fsck.c
  118. fsck.h
  119. generate-cmdlist.sh
  120. gettext.c
  121. gettext.h
  122. git-add--interactive.perl
  123. git-archimport.perl
  124. git-bisect.sh
  125. git-compat-util.h
  126. git-cvsexportcommit.perl
  127. git-cvsimport.perl
  128. git-cvsserver.perl
  129. git-difftool--helper.sh
  130. git-difftool.perl
  131. git-filter-branch.sh
  132. git-instaweb.sh
  133. git-merge-octopus.sh
  134. git-merge-one-file.sh
  135. git-merge-resolve.sh
  136. git-mergetool--lib.sh
  137. git-mergetool.sh
  138. git-p4.py
  139. git-parse-remote.sh
  140. git-quiltimport.sh
  141. git-rebase--am.sh
  142. git-rebase--interactive.sh
  143. git-rebase--merge.sh
  144. git-rebase.sh
  145. git-relink.perl
  146. git-remote-testgit.sh
  147. git-request-pull.sh
  148. git-send-email.perl
  149. git-sh-i18n.sh
  150. git-sh-setup.sh
  151. git-stash.sh
  152. git-submodule.sh
  153. git-svn.perl
  154. GIT-VERSION-GEN
  155. git-web--browse.sh
  156. git.c
  157. git.rc
  158. gpg-interface.c
  159. gpg-interface.h
  160. graph.c
  161. graph.h
  162. grep.c
  163. grep.h
  164. hashmap.c
  165. hashmap.h
  166. help.c
  167. help.h
  168. hex.c
  169. http-backend.c
  170. http-fetch.c
  171. http-push.c
  172. http-walker.c
  173. http.c
  174. http.h
  175. ident.c
  176. imap-send.c
  177. INSTALL
  178. iterator.h
  179. khash.h
  180. kwset.c
  181. kwset.h
  182. levenshtein.c
  183. levenshtein.h
  184. LGPL-2.1
  185. line-log.c
  186. line-log.h
  187. line-range.c
  188. line-range.h
  189. list-objects.c
  190. list-objects.h
  191. list.h
  192. ll-merge.c
  193. ll-merge.h
  194. lockfile.c
  195. lockfile.h
  196. log-tree.c
  197. log-tree.h
  198. mailinfo.c
  199. mailinfo.h
  200. mailmap.c
  201. mailmap.h
  202. Makefile
  203. match-trees.c
  204. merge-blobs.c
  205. merge-blobs.h
  206. merge-recursive.c
  207. merge-recursive.h
  208. merge.c
  209. mergesort.c
  210. mergesort.h
  211. mru.c
  212. mru.h
  213. name-hash.c
  214. notes-cache.c
  215. notes-cache.h
  216. notes-merge.c
  217. notes-merge.h
  218. notes-utils.c
  219. notes-utils.h
  220. notes.c
  221. notes.h
  222. object.c
  223. object.h
  224. pack-bitmap-write.c
  225. pack-bitmap.c
  226. pack-bitmap.h
  227. pack-check.c
  228. pack-objects.c
  229. pack-objects.h
  230. pack-revindex.c
  231. pack-revindex.h
  232. pack-write.c
  233. pack.h
  234. pager.c
  235. parse-options-cb.c
  236. parse-options.c
  237. parse-options.h
  238. patch-delta.c
  239. patch-ids.c
  240. patch-ids.h
  241. path.c
  242. pathspec.c
  243. pathspec.h
  244. pkt-line.c
  245. pkt-line.h
  246. preload-index.c
  247. pretty.c
  248. prio-queue.c
  249. prio-queue.h
  250. progress.c
  251. progress.h
  252. prompt.c
  253. prompt.h
  254. quote.c
  255. quote.h
  256. reachable.c
  257. reachable.h
  258. read-cache.c
  259. README.md
  260. ref-filter.c
  261. ref-filter.h
  262. reflog-walk.c
  263. reflog-walk.h
  264. refs.c
  265. refs.h
  266. remote-curl.c
  267. remote-testsvn.c
  268. remote.c
  269. remote.h
  270. replace_object.c
  271. rerere.c
  272. rerere.h
  273. resolve-undo.c
  274. resolve-undo.h
  275. revision.c
  276. revision.h
  277. run-command.c
  278. run-command.h
  279. send-pack.c
  280. send-pack.h
  281. sequencer.c
  282. sequencer.h
  283. server-info.c
  284. setup.c
  285. sh-i18n--envsubst.c
  286. sha1-array.c
  287. sha1-array.h
  288. sha1-lookup.c
  289. sha1-lookup.h
  290. sha1_file.c
  291. sha1_name.c
  292. shallow.c
  293. shell.c
  294. shortlog.h
  295. show-index.c
  296. sideband.c
  297. sideband.h
  298. sigchain.c
  299. sigchain.h
  300. split-index.c
  301. split-index.h
  302. strbuf.c
  303. strbuf.h
  304. streaming.c
  305. streaming.h
  306. string-list.c
  307. string-list.h
  308. submodule-config.c
  309. submodule-config.h
  310. submodule.c
  311. submodule.h
  312. symlinks.c
  313. tag.c
  314. tag.h
  315. tar.h
  316. tempfile.c
  317. tempfile.h
  318. thread-utils.c
  319. thread-utils.h
  320. tmp-objdir.c
  321. tmp-objdir.h
  322. trace.c
  323. trace.h
  324. trailer.c
  325. trailer.h
  326. transport-helper.c
  327. transport.c
  328. transport.h
  329. tree-diff.c
  330. tree-walk.c
  331. tree-walk.h
  332. tree.c
  333. tree.h
  334. unicode_width.h
  335. unimplemented.sh
  336. unix-socket.c
  337. unix-socket.h
  338. unpack-trees.c
  339. unpack-trees.h
  340. update_unicode.sh
  341. upload-pack.c
  342. url.c
  343. url.h
  344. urlmatch.c
  345. urlmatch.h
  346. usage.c
  347. userdiff.c
  348. userdiff.h
  349. utf8.c
  350. utf8.h
  351. varint.c
  352. varint.h
  353. version.c
  354. version.h
  355. versioncmp.c
  356. walker.c
  357. walker.h
  358. wildmatch.c
  359. wildmatch.h
  360. worktree.c
  361. worktree.h
  362. wrap-for-bin.sh
  363. wrapper.c
  364. write_or_die.c
  365. ws.c
  366. wt-status.c
  367. wt-status.h
  368. xdiff-interface.c
  369. xdiff-interface.h
  370. zlib.c
README.md

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