submodule add: Fail when .git/modules/<name> already exists unless forced

When adding a new submodule it can happen that .git/modules/<name> already
contains a submodule repo, e.g. when a submodule is removed from the work
tree and another submodule is added at the same path. But then the work
tree of the submodule will be populated using the existing repository and
not the one the user provided, which results in an incorrect work tree. On
the other hand the user might reactivate a submodule removed earlier, then
reusing that .git directory is the Right Thing to do.

As git can't decide what is the case, error out and tell the user she
should use either use a different name for the submodule with the "--name"
option or can reuse the .git directory for the newly added submodule by
providing the --force option (which only makes sense when the upstream
matches, so the error message lists all remotes of .git/modules/<name>).

In one test in t7406 the --force option had to be added to "git submodule
add", as that test re-adds a formerly removed submodule.

Reported-by: Jonathan Johnson <me@jondavidjohn.com>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
3 files changed
tree: 6825a9ffe4b1467939ea77c1b513dd368abdfd8a
  1. block-sha1/
  2. builtin/
  3. compat/
  4. contrib/
  5. Documentation/
  6. git-gui/
  7. git_remote_helpers/
  8. gitk-git/
  9. gitweb/
  10. mergetools/
  11. perl/
  12. po/
  13. ppc/
  14. t/
  15. templates/
  16. vcs-svn/
  17. xdiff/
  18. .gitattributes
  19. .gitignore
  20. .mailmap
  21. abspath.c
  22. aclocal.m4
  23. advice.c
  24. advice.h
  25. alias.c
  26. alloc.c
  27. archive-tar.c
  28. archive-zip.c
  29. archive.c
  30. archive.h
  31. argv-array.c
  32. argv-array.h
  33. attr.c
  34. attr.h
  35. base85.c
  36. bisect.c
  37. bisect.h
  38. blob.c
  39. blob.h
  40. branch.c
  41. branch.h
  42. builtin.h
  43. bulk-checkin.c
  44. bulk-checkin.h
  45. bundle.c
  46. bundle.h
  47. cache-tree.c
  48. cache-tree.h
  49. cache.h
  50. check-builtins.sh
  51. check-racy.c
  52. check_bindir
  53. color.c
  54. color.h
  55. column.c
  56. column.h
  57. combine-diff.c
  58. command-list.txt
  59. commit.c
  60. commit.h
  61. config.c
  62. config.mak.in
  63. configure.ac
  64. connect.c
  65. connected.c
  66. connected.h
  67. convert.c
  68. convert.h
  69. copy.c
  70. COPYING
  71. credential-cache--daemon.c
  72. credential-cache.c
  73. credential-store.c
  74. credential.c
  75. credential.h
  76. csum-file.c
  77. csum-file.h
  78. ctype.c
  79. daemon.c
  80. date.c
  81. decorate.c
  82. decorate.h
  83. delta.h
  84. diff-delta.c
  85. diff-lib.c
  86. diff-no-index.c
  87. diff.c
  88. diff.h
  89. diffcore-break.c
  90. diffcore-delta.c
  91. diffcore-order.c
  92. diffcore-pickaxe.c
  93. diffcore-rename.c
  94. diffcore.h
  95. dir.c
  96. dir.h
  97. editor.c
  98. entry.c
  99. environment.c
  100. exec_cmd.c
  101. exec_cmd.h
  102. fast-import.c
  103. fetch-pack.h
  104. fixup-builtins
  105. fmt-merge-msg.h
  106. fsck.c
  107. fsck.h
  108. generate-cmdlist.sh
  109. gettext.c
  110. gettext.h
  111. git-add--interactive.perl
  112. git-am.sh
  113. git-archimport.perl
  114. git-bisect.sh
  115. git-compat-util.h
  116. git-cvsexportcommit.perl
  117. git-cvsimport.perl
  118. git-cvsserver.perl
  119. git-difftool--helper.sh
  120. git-difftool.perl
  121. git-filter-branch.sh
  122. git-instaweb.sh
  123. git-lost-found.sh
  124. git-merge-octopus.sh
  125. git-merge-one-file.sh
  126. git-merge-resolve.sh
  127. git-mergetool--lib.sh
  128. git-mergetool.sh
  129. git-p4.py
  130. git-parse-remote.sh
  131. git-pull.sh
  132. git-quiltimport.sh
  133. git-rebase--am.sh
  134. git-rebase--interactive.sh
  135. git-rebase--merge.sh
  136. git-rebase.sh
  137. git-relink.perl
  138. git-remote-testgit.py
  139. git-repack.sh
  140. git-request-pull.sh
  141. git-send-email.perl
  142. git-sh-i18n.sh
  143. git-sh-setup.sh
  144. git-stash.sh
  145. git-submodule.sh
  146. git-svn.perl
  147. GIT-VERSION-GEN
  148. git-web--browse.sh
  149. git.c
  150. git.spec.in
  151. gpg-interface.c
  152. gpg-interface.h
  153. graph.c
  154. graph.h
  155. grep.c
  156. grep.h
  157. hash.c
  158. hash.h
  159. help.c
  160. help.h
  161. hex.c
  162. http-backend.c
  163. http-fetch.c
  164. http-push.c
  165. http-walker.c
  166. http.c
  167. http.h
  168. ident.c
  169. imap-send.c
  170. INSTALL
  171. kwset.c
  172. kwset.h
  173. levenshtein.c
  174. levenshtein.h
  175. LGPL-2.1
  176. list-objects.c
  177. list-objects.h
  178. ll-merge.c
  179. ll-merge.h
  180. lockfile.c
  181. log-tree.c
  182. log-tree.h
  183. mailmap.c
  184. mailmap.h
  185. Makefile
  186. match-trees.c
  187. merge-file.c
  188. merge-file.h
  189. merge-recursive.c
  190. merge-recursive.h
  191. mergesort.c
  192. mergesort.h
  193. name-hash.c
  194. notes-cache.c
  195. notes-cache.h
  196. notes-merge.c
  197. notes-merge.h
  198. notes.c
  199. notes.h
  200. object.c
  201. object.h
  202. pack-check.c
  203. pack-refs.c
  204. pack-refs.h
  205. pack-revindex.c
  206. pack-revindex.h
  207. pack-write.c
  208. pack.h
  209. pager.c
  210. parse-options-cb.c
  211. parse-options.c
  212. parse-options.h
  213. patch-delta.c
  214. patch-ids.c
  215. patch-ids.h
  216. path.c
  217. pkt-line.c
  218. pkt-line.h
  219. preload-index.c
  220. pretty.c
  221. progress.c
  222. progress.h
  223. prompt.c
  224. prompt.h
  225. quote.c
  226. quote.h
  227. reachable.c
  228. reachable.h
  229. read-cache.c
  230. README
  231. reflog-walk.c
  232. reflog-walk.h
  233. refs.c
  234. refs.h
  235. remote-curl.c
  236. remote.c
  237. remote.h
  238. replace_object.c
  239. rerere.c
  240. rerere.h
  241. resolve-undo.c
  242. resolve-undo.h
  243. revision.c
  244. revision.h
  245. run-command.c
  246. run-command.h
  247. send-pack.h
  248. sequencer.c
  249. sequencer.h
  250. server-info.c
  251. setup.c
  252. sh-i18n--envsubst.c
  253. sha1-array.c
  254. sha1-array.h
  255. sha1-lookup.c
  256. sha1-lookup.h
  257. sha1_file.c
  258. sha1_name.c
  259. shallow.c
  260. shell.c
  261. shortlog.h
  262. show-index.c
  263. sideband.c
  264. sideband.h
  265. sigchain.c
  266. sigchain.h
  267. strbuf.c
  268. strbuf.h
  269. streaming.c
  270. streaming.h
  271. string-list.c
  272. string-list.h
  273. submodule.c
  274. submodule.h
  275. symlinks.c
  276. tag.c
  277. tag.h
  278. tar.h
  279. test-chmtime.c
  280. test-ctype.c
  281. test-date.c
  282. test-delta.c
  283. test-dump-cache-tree.c
  284. test-genrandom.c
  285. test-index-version.c
  286. test-line-buffer.c
  287. test-match-trees.c
  288. test-mergesort.c
  289. test-mktemp.c
  290. test-parse-options.c
  291. test-path-utils.c
  292. test-regex.c
  293. test-revision-walking.c
  294. test-run-command.c
  295. test-scrap-cache-tree.c
  296. test-sha1.c
  297. test-sha1.sh
  298. test-sigchain.c
  299. test-string-list.c
  300. test-subprocess.c
  301. test-svn-fe.c
  302. thread-utils.c
  303. thread-utils.h
  304. trace.c
  305. transport-helper.c
  306. transport.c
  307. transport.h
  308. tree-diff.c
  309. tree-walk.c
  310. tree-walk.h
  311. tree.c
  312. tree.h
  313. unimplemented.sh
  314. unix-socket.c
  315. unix-socket.h
  316. unpack-trees.c
  317. unpack-trees.h
  318. upload-pack.c
  319. url.c
  320. url.h
  321. usage.c
  322. userdiff.c
  323. userdiff.h
  324. utf8.c
  325. utf8.h
  326. varint.c
  327. varint.h
  328. version.c
  329. version.h
  330. walker.c
  331. walker.h
  332. wrap-for-bin.sh
  333. wrapper.c
  334. write_or_die.c
  335. ws.c
  336. wt-status.c
  337. wt-status.h
  338. xdiff-interface.c
  339. xdiff-interface.h
  340. zlib.c