graph: indent visual root in graph

When rendering a graph, if the history contains multiple "visual roots",
actual roots or commits that look like roots (i.e. have their parents
filtered out) can end up being vertically adjacent to unrelated commits,
falsely appearing to be related.

A fix for this issue was already attempted [1] a while ago.

This happens because the commits fill the space from left to right and
when a visual root ends, its column becomes free for the following
commit even if they are not related. Once this happens the unrelated
commit is rendered below the visual root. Because there is no special
character or way to identify when a visual root is rendered making the
graph confusing.

By indenting the visual roots when there are still commits to show the
vertical adjacency can be avoided.

Add is_visual_root flag to git_graph making it visible in all graph states,
give graph_update() a new function, graph_is_visual_root() to know if the
current commit is a visual root and set is_visual_root.
The different handled cases are:

- If a visual root has children: similar to GRAPH_PRE_COMMIT state when
  octopus merges need space, an edge row needs to be printed to connect
  the child with the indented visual root. A new state GRAPH_PRE_ROOT is
  needed to connect the child with the visual root:

    * child of the visual root
     \ GRAPH_PRE_ROOT
      * visual root indented

- If a visual root is child-less we can skip GRAPH_PRE_ROOT state and
  render the indented commit directly.

      * visual root indented
    * unrelated commit

- If two or more visual roots are adjacent: by having a lookahead to the
  next commit that will be rendered, if the next commit is also a visual
  root and we are on a visual root, meaning two visual root adjacent in
  the history, the top one can omit the indent, making the one below to
  indent only once, if there are more adjacent visual commits, the
  indentation will increase for each adjacent one, cascading.

    * visual root
      * visual root
        * visual root
    * last commit

  Even if the last commit is a root, because there is nothing that will be
  rendered below we can omit the indentation on purpose.

[1]: https://lore.kernel.org/git/xmqqwnwajbuj.fsf@gitster.c.googlers.com/

Helped-by: Kristofer Karlsson <krka@spotify.com>
Mentored-by: Karthik Nayak <karthik.188@gmail.com>
Mentored-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Pablo Sabater <pabloosabaterr@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
3 files changed
tree: 9e61f2c95bf87e381dbba10061271e43f22d29c5
  1. .github/
  2. bin-wrappers/
  3. block-sha1/
  4. builtin/
  5. ci/
  6. compat/
  7. compiler-tricks/
  8. contrib/
  9. Documentation/
  10. ewah/
  11. git-gui/
  12. gitk-git/
  13. gitweb/
  14. mergetools/
  15. negotiator/
  16. odb/
  17. oss-fuzz/
  18. perl/
  19. po/
  20. refs/
  21. reftable/
  22. sha1/
  23. sha1dc/
  24. sha256/
  25. src/
  26. subprojects/
  27. t/
  28. templates/
  29. tools/
  30. trace2/
  31. xdiff/
  32. .b4-config
  33. .b4-cover-template
  34. .cirrus.yml
  35. .clang-format
  36. .editorconfig
  37. .gitattributes
  38. .gitignore
  39. .gitlab-ci.yml
  40. .gitmodules
  41. .mailmap
  42. .tsan-suppressions
  43. abspath.c
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  45. aclocal.m4
  46. add-interactive.c
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  48. add-patch.c
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  50. advice.c
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  52. alias.c
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  54. alloc.c
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  58. archive-tar.c
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  62. attr.c
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  75. branch.c
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  77. build.rs
  78. builtin.h
  79. bundle-uri.c
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  83. cache-tree.c
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  85. Cargo.toml
  86. cbtree.c
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  88. chdir-notify.c
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  90. checkout.c
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  92. chunk-format.c
  93. chunk-format.h
  94. CODE_OF_CONDUCT.md
  95. color.c
  96. color.h
  97. column.c
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  99. combine-diff.c
  100. command-list.txt
  101. commit-graph.c
  102. commit-graph.h
  103. commit-reach.c
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  105. commit-slab-decl.h
  106. commit-slab-impl.h
  107. commit-slab.h
  108. commit.c
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  110. common-exit.c
  111. common-init.c
  112. common-init.h
  113. common-main.c
  114. config.c
  115. config.h
  116. config.mak.dev
  117. config.mak.in
  118. config.mak.uname
  119. configure.ac
  120. connect.c
  121. connect.h
  122. connected.c
  123. connected.h
  124. convert.c
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  126. copy.c
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  128. COPYING
  129. credential.c
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  131. csum-file.c
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  133. ctype.c
  134. daemon.c
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  139. delta-islands.c
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  142. diagnose.c
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  144. diff-delta.c
  145. diff-lib.c
  146. diff-merges.c
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  148. diff-no-index.c
  149. diff.c
  150. diff.h
  151. diffcore-break.c
  152. diffcore-delta.c
  153. diffcore-order.c
  154. diffcore-pickaxe.c
  155. diffcore-rename.c
  156. diffcore-rotate.c
  157. diffcore.h
  158. dir-iterator.c
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  160. dir.c
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  162. editor.c
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  164. entry.c
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  166. environment.c
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  168. exec-cmd.c
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  170. fetch-negotiator.c
  171. fetch-negotiator.h
  172. fetch-pack.c
  173. fetch-pack.h
  174. fmt-merge-msg.c
  175. fmt-merge-msg.h
  176. for-each-ref.h
  177. fsck.c
  178. fsck.h
  179. fsmonitor--daemon.h
  180. fsmonitor-ipc.c
  181. fsmonitor-ipc.h
  182. fsmonitor-ll.h
  183. fsmonitor-path-utils.h
  184. fsmonitor-settings.c
  185. fsmonitor-settings.h
  186. fsmonitor.c
  187. fsmonitor.h
  188. gettext.c
  189. gettext.h
  190. git-archimport.perl
  191. GIT-BUILD-OPTIONS.in
  192. git-compat-util.h
  193. git-curl-compat.h
  194. git-cvsexportcommit.perl
  195. git-cvsimport.perl
  196. git-cvsserver.perl
  197. git-difftool--helper.sh
  198. git-filter-branch.sh
  199. git-instaweb.sh
  200. git-merge-octopus.sh
  201. git-merge-one-file.sh
  202. git-merge-resolve.sh
  203. git-mergetool--lib.sh
  204. git-mergetool.sh
  205. git-p4.py
  206. git-quiltimport.sh
  207. git-request-pull.sh
  208. git-send-email.perl
  209. git-sh-i18n.sh
  210. git-sh-setup.sh
  211. git-submodule.sh
  212. git-svn.perl
  213. GIT-VERSION-FILE.in
  214. GIT-VERSION-GEN
  215. git-web--browse.sh
  216. git-zlib.c
  217. git-zlib.h
  218. git.c
  219. git.rc.in
  220. gpg-interface.c
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  222. graph.c
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  224. grep.c
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  230. hashmap.c
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  232. help.c
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  235. hex-ll.h
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  238. hook.c
  239. hook.h
  240. http-backend.c
  241. http-fetch.c
  242. http-push.c
  243. http-walker.c
  244. http.c
  245. http.h
  246. ident.c
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  248. imap-send.c
  249. INSTALL
  250. iterator.h
  251. json-writer.c
  252. json-writer.h
  253. khash.h
  254. kwset.c
  255. kwset.h
  256. levenshtein.c
  257. levenshtein.h
  258. LGPL-2.1
  259. line-log.c
  260. line-log.h
  261. line-range.c
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  263. linear-assignment.c
  264. linear-assignment.h
  265. list-objects-filter-options.c
  266. list-objects-filter-options.h
  267. list-objects-filter.c
  268. list-objects-filter.h
  269. list-objects.c
  270. list-objects.h
  271. list.h
  272. lockfile.c
  273. lockfile.h
  274. log-tree.c
  275. log-tree.h
  276. loose.c
  277. loose.h
  278. ls-refs.c
  279. ls-refs.h
  280. mailinfo.c
  281. mailinfo.h
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  283. mailmap.h
  284. Makefile
  285. match-trees.c
  286. match-trees.h
  287. mem-pool.c
  288. mem-pool.h
  289. merge-blobs.c
  290. merge-blobs.h
  291. merge-ll.c
  292. merge-ll.h
  293. merge-ort-wrappers.c
  294. merge-ort-wrappers.h
  295. merge-ort.c
  296. merge-ort.h
  297. merge.c
  298. merge.h
  299. mergesort.h
  300. meson.build
  301. meson_options.txt
  302. midx-write.c
  303. midx.c
  304. midx.h
  305. name-hash.c
  306. name-hash.h
  307. notes-cache.c
  308. notes-cache.h
  309. notes-merge.c
  310. notes-merge.h
  311. notes-utils.c
  312. notes-utils.h
  313. notes.c
  314. notes.h
  315. object-file-convert.c
  316. object-file-convert.h
  317. object-file.c
  318. object-file.h
  319. object-name.c
  320. object-name.h
  321. object.c
  322. object.h
  323. odb.c
  324. odb.h
  325. oid-array.c
  326. oid-array.h
  327. oidmap.c
  328. oidmap.h
  329. oidset.c
  330. oidset.h
  331. oidtree.c
  332. oidtree.h
  333. pack-bitmap-write.c
  334. pack-bitmap.c
  335. pack-bitmap.h
  336. pack-check.c
  337. pack-mtimes.c
  338. pack-mtimes.h
  339. pack-objects.c
  340. pack-objects.h
  341. pack-refs.c
  342. pack-refs.h
  343. pack-revindex.c
  344. pack-revindex.h
  345. pack-write.c
  346. pack.h
  347. packfile-list.c
  348. packfile-list.h
  349. packfile.c
  350. packfile.h
  351. pager.c
  352. pager.h
  353. parallel-checkout.c
  354. parallel-checkout.h
  355. parse-options-cb.c
  356. parse-options.c
  357. parse-options.h
  358. parse.c
  359. parse.h
  360. patch-delta.c
  361. patch-ids.c
  362. patch-ids.h
  363. path-walk.c
  364. path-walk.h
  365. path.c
  366. path.h
  367. pathspec.c
  368. pathspec.h
  369. pkt-line.c
  370. pkt-line.h
  371. preload-index.c
  372. preload-index.h
  373. pretty.c
  374. pretty.h
  375. prio-queue.c
  376. prio-queue.h
  377. progress.c
  378. progress.h
  379. promisor-remote.c
  380. promisor-remote.h
  381. prompt.c
  382. prompt.h
  383. protocol-caps.c
  384. protocol-caps.h
  385. protocol.c
  386. protocol.h
  387. prune-packed.c
  388. prune-packed.h
  389. pseudo-merge.c
  390. pseudo-merge.h
  391. quote.c
  392. quote.h
  393. range-diff.c
  394. range-diff.h
  395. reachable.c
  396. reachable.h
  397. read-cache-ll.h
  398. read-cache.c
  399. read-cache.h
  400. README.md
  401. rebase-interactive.c
  402. rebase-interactive.h
  403. rebase.c
  404. rebase.h
  405. ref-filter.c
  406. ref-filter.h
  407. reflog-walk.c
  408. reflog-walk.h
  409. reflog.c
  410. reflog.h
  411. refs.c
  412. refs.h
  413. refspec.c
  414. refspec.h
  415. remote-curl.c
  416. remote.c
  417. remote.h
  418. repack-cruft.c
  419. repack-filtered.c
  420. repack-geometry.c
  421. repack-midx.c
  422. repack-promisor.c
  423. repack.c
  424. repack.h
  425. replace-object.c
  426. replace-object.h
  427. replay.c
  428. replay.h
  429. repo-settings.c
  430. repo-settings.h
  431. repository.c
  432. repository.h
  433. rerere.c
  434. rerere.h
  435. reset.c
  436. reset.h
  437. resolve-undo.c
  438. resolve-undo.h
  439. revision.c
  440. revision.h
  441. run-command.c
  442. run-command.h
  443. sane-ctype.h
  444. scalar.c
  445. SECURITY.md
  446. send-pack.c
  447. send-pack.h
  448. sequencer.c
  449. sequencer.h
  450. serve.c
  451. serve.h
  452. server-info.c
  453. server-info.h
  454. setup.c
  455. setup.h
  456. sh-i18n--envsubst.c
  457. sha1dc_git.c
  458. sha1dc_git.h
  459. shallow.c
  460. shallow.h
  461. shared.mak
  462. shell.c
  463. shortlog.h
  464. sideband.c
  465. sideband.h
  466. sigchain.c
  467. sigchain.h
  468. simple-ipc.h
  469. sparse-index.c
  470. sparse-index.h
  471. split-index.c
  472. split-index.h
  473. stable-qsort.c
  474. statinfo.c
  475. statinfo.h
  476. strbuf.c
  477. strbuf.h
  478. string-list.c
  479. string-list.h
  480. strmap.c
  481. strmap.h
  482. strvec.c
  483. strvec.h
  484. sub-process.c
  485. sub-process.h
  486. submodule-config.c
  487. submodule-config.h
  488. submodule.c
  489. submodule.h
  490. symlinks.c
  491. symlinks.h
  492. tag.c
  493. tag.h
  494. tar.h
  495. tempfile.c
  496. tempfile.h
  497. thread-utils.c
  498. thread-utils.h
  499. tmp-objdir.c
  500. tmp-objdir.h
  501. trace.c
  502. trace.h
  503. trace2.c
  504. trace2.h
  505. trailer.c
  506. trailer.h
  507. transport-helper.c
  508. transport-internal.h
  509. transport.c
  510. transport.h
  511. tree-diff.c
  512. tree-walk.c
  513. tree-walk.h
  514. tree.c
  515. tree.h
  516. unicode-width.h
  517. unimplemented.sh
  518. unix-socket.c
  519. unix-socket.h
  520. unix-stream-server.c
  521. unix-stream-server.h
  522. unpack-trees.c
  523. unpack-trees.h
  524. upload-pack.c
  525. upload-pack.h
  526. url.c
  527. url.h
  528. urlmatch.c
  529. urlmatch.h
  530. usage.c
  531. userdiff.c
  532. userdiff.h
  533. utf8.c
  534. utf8.h
  535. varint.c
  536. varint.h
  537. version-def.h.in
  538. version.c
  539. version.h
  540. versioncmp.c
  541. versioncmp.h
  542. walker.c
  543. walker.h
  544. wildmatch.c
  545. wildmatch.h
  546. worktree.c
  547. worktree.h
  548. wrapper.c
  549. wrapper.h
  550. write-or-die.c
  551. write-or-die.h
  552. ws.c
  553. ws.h
  554. wt-status.c
  555. wt-status.h
  556. xdiff-interface.c
  557. 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.adoc to get started, then see Documentation/giteveryday.adoc for a useful minimum set of commands, and Documentation/git-<commandname>.adoc 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.adoc (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 to git+subscribe@vger.kernel.org (see https://subspace.kernel.org/subscribing.html for details). The mailing list archives are available at https://lore.kernel.org/git/, https://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