subtree: give the docs a once-over

Just went through the docs looking for anything inaccurate or that can be improved. In the '-h' text, in the man page synopsis, and in the man page description: Normalize the ordering of the list of sub-commands: 'add', 'merge', 'split', 'pull', 'push'. This allows us to kinda separate the lower-level add/merge/split from the higher-level pull/push. '-h' text: - correction: Indicate that split's arg is optional. - clarity: Emphasize that 'pull' takes the 'add'/'merge' flags. man page: - correction: State that all subcommands take options (it seemed to indicate that only 'split' takes any options other than '-P'). - correction: 'split' only guarantees that the results are identical if the flags are identical. - correction: The flag is named '--ignore-joins', not '--ignore-join'. - completeness: Clarify that 'push' always operates on HEAD, and that 'split' operates on HEAD if no local commit is given. - clarity: In the description, when listing commands, repeat what their arguments are. This way the reader doesn't need to flip back and forth between the command description and the synopsis and the full description to understand what's being said. - clarity: In the <variables> used to give command arguments, give slightly longer, descriptive names. Like <local-commit> instead of just <commit>. - clarity: Emphasize that 'pull' takes the 'add'/'merge' flags. - style: In the synopsis, list options before the subcommand. This makes things line up and be much more readable when shown non-monospace (such as in `make html`), and also more closely matches other man pages (like `git-submodule.txt`). - style: Use the correct syntax for indicating the options ([<options>] instead of [OPTIONS]). - style: In the synopsis, separate 'pull' and 'push' from the other lower-level commands. I think this helps readability. - style: Code-quote things in prose that seem like they should be code-quoted, like '.gitmodules', flags, or full commands. - style: Minor wording improvements, like more consistent mood (many of the command descriptions start in the imperative mood and switch to the indicative mode by the end). That sort of thing. - style: Capitalize "ID". - style: Remove the "This option is only valid for XXX command" remarks from each option, and instead rely on the section headings. - style: Since that line is getting edited anyway, switch "behaviour" to American "behavior". - style: Trim trailing whitespace. `todo`: - style: Trim trailing whitespace. Signed-off-by: Luke Shumaker <lukeshu@datawire.io> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Luke Shumaker committed Apr 27, 2021 at 15:17 UTC 6468784dd2ca3ea2408f9915ab9b7ce136f0b024
3 files changed +87 -93
contrib/subtree/git-subtree.sh
+2 -2
@@ -25,9 +25,9 @@ OPTS_SPEC="\
25 git subtree add --prefix=<prefix> <commit>
26 git subtree add --prefix=<prefix> <repository> <ref>
27 git subtree merge --prefix=<prefix> <commit>
28 +git subtree split --prefix=<prefix> [<commit>]
29 git subtree pull --prefix=<prefix> <repository> <ref>
30 git subtree push --prefix=<prefix> <repository> <ref>
30 -git subtree split --prefix=<prefix> <commit>
31 --
32 h,help show the help
33 q quiet
@@ -40,7 +40,7 @@ b,branch= create a new branch from the split subtree
40 ignore-joins ignore prior --rejoin commits
41 onto= try connecting new tree to an existing one
42 rejoin merge the new branch back into HEAD
43 - options for 'add', 'merge', and 'pull'
43 + options for 'add' and 'merge' (also: 'pull')
44 squash merge subtree changes as a single commit
45 "
46
contrib/subtree/git-subtree.txt
+82 -88
@@ -9,13 +9,14 @@ git-subtree - Merge subtrees together and split repository into subtrees
9 SYNOPSIS
10 --------
11 [verse]
12 -'git subtree' add -P <prefix> <commit>
13 -'git subtree' add -P <prefix> <repository> <ref>
14 -'git subtree' pull -P <prefix> <repository> <ref>
15 -'git subtree' push -P <prefix> <repository> <ref>
16 -'git subtree' merge -P <prefix> <commit>
17 -'git subtree' split -P <prefix> [OPTIONS] [<commit>]
12 +'git subtree' [<options>] -P <prefix> add <local-commit>
13 +'git subtree' [<options>] -P <prefix> add <repository> <remote-ref>
14 +'git subtree' [<options>] -P <prefix> merge <local-commit>
15 +'git subtree' [<options>] -P <prefix> split [<local-commit>]
16
17 +[verse]
18 +'git subtree' [<options>] -P <prefix> pull <repository> <remote-ref>
19 +'git subtree' [<options>] -P <prefix> push <repository> <remote-ref>
20
21 DESCRIPTION
22 -----------
@@ -28,7 +29,7 @@ as a subdirectory of your application.
29
30 Subtrees are not to be confused with submodules, which are meant for
31 the same task. Unlike submodules, subtrees do not need any special
31 -constructions (like .gitmodules files or gitlinks) be present in
32 +constructions (like '.gitmodules' files or gitlinks) be present in
33 your repository, and do not force end-users of your
34 repository to do anything special or to understand how subtrees
35 work. A subtree is just a subdirectory that can be
@@ -59,67 +60,69 @@ project as much as possible. That is, if you make a change that
60 affects both the library and the main application, commit it in
61 two pieces. That way, when you split the library commits out
62 later, their descriptions will still make sense. But if this
62 -isn't important to you, it's not *necessary*. git subtree will
63 +isn't important to you, it's not *necessary*. 'git subtree' will
64 simply leave out the non-library-related parts of the commit
65 when it splits it out into the subproject later.
66
67
68 COMMANDS
69 --------
69 -add::
70 +add <local-commit>::
71 +add <repository> <remote-ref>::
72 Create the <prefix> subtree by importing its contents
71 - from the given <commit> or <repository> and remote <ref>.
73 + from the given <local-commit> or <repository> and <remote-ref>.
74 A new commit is created automatically, joining the imported
73 - project's history with your own. With '--squash', imports
75 + project's history with your own. With '--squash', import
76 only a single commit from the subproject, rather than its
77 entire history.
78
77 -merge::
78 - Merge recent changes up to <commit> into the <prefix>
79 +merge <local-commit>::
80 + Merge recent changes up to <local-commit> into the <prefix>
81 subtree. As with normal 'git merge', this doesn't
82 remove your own local changes; it just merges those
81 - changes into the latest <commit>. With '--squash',
82 - creates only one commit that contains all the changes,
83 + changes into the latest <local-commit>. With '--squash',
84 + create only one commit that contains all the changes,
85 rather than merging in the entire history.
86 +
87 If you use '--squash', the merge direction doesn't always have to be
88 forward; you can use this command to go back in time from v2.5 to v2.4,
89 for example. If your merge introduces a conflict, you can resolve it in
90 the usual ways.
89 -
90 -pull::
91 - Exactly like 'merge', but parallels 'git pull' in that
92 - it fetches the given ref from the specified remote
93 - repository.
94 -
95 -push::
96 - Does a 'split' (see below) using the <prefix> supplied
97 - and then does a 'git push' to push the result to the
98 - repository and ref. This can be used to push your
99 - subtree to different branches of the remote repository.
100 -
101 -split::
91 +
92 +split [<local-commit>]::
93 Extract a new, synthetic project history from the
103 - history of the <prefix> subtree. The new history
94 + history of the <prefix> subtree of <local-commit>, or of
95 + HEAD if no <local-commit> is given. The new history
96 includes only the commits (including merges) that
97 affected <prefix>, and each of those commits now has the
98 contents of <prefix> at the root of the project instead
99 of in a subdirectory. Thus, the newly created history
100 is suitable for export as a separate git repository.
101 +
110 -After splitting successfully, a single commit id is printed to stdout.
102 +After splitting successfully, a single commit ID is printed to stdout.
103 This corresponds to the HEAD of the newly created tree, which you can
104 manipulate however you want.
105 +
106 Repeated splits of exactly the same history are guaranteed to be
115 -identical (i.e. to produce the same commit ids). Because of this, if
116 -you add new commits and then re-split, the new commits will be attached
117 -as commits on top of the history you generated last time, so 'git merge'
118 -and friends will work as expected.
107 +identical (i.e. to produce the same commit IDs) as long as the
108 +settings passed to 'split' (such as '--annotate') are the same.
109 +Because of this, if you add new commits and then re-split, the new
110 +commits will be attached as commits on top of the history you
111 +generated last time, so 'git merge' and friends will work as expected.
112 +
113 Note that if you use '--squash' when you merge, you should usually not
114 just '--rejoin' when you split.
115
116 +pull <repository> <remote-ref>::
117 + Exactly like 'merge', but parallels 'git pull' in that
118 + it fetches the given ref from the specified remote
119 + repository.
120 +
121 +push <repository> <remote-ref>::
122 + Does a 'split' using the <prefix> subtree of HEAD and then
123 + does a 'git push' to push the result to the <repository> and
124 + <remote-ref>. This can be used to push your subtree to
125 + different branches of the remote repository.
126
127 OPTIONS
128 -------
@@ -139,19 +142,18 @@ OPTIONS
142
143 -m <message>::
144 --message=<message>::
142 - This option is only valid for add, merge, pull, and split --rejoin.
145 + This option is only valid for 'add', 'merge', 'pull', and 'split --rejoin'.
146 Specify <message> as the commit message for the merge commit.
147
148 +OPTIONS FOR 'add' AND 'merge' (ALSO: 'pull')
149 +--------------------------------------------
150 +These options for 'add' and 'merge' may also be given to 'pull' (which
151 +wraps 'merge').
152
146 -OPTIONS FOR add, merge, and pull
147 ---------------------------------
153 --squash::
149 - This option is only valid for add, merge, and pull
150 - commands.
151 -+
152 -Instead of merging the entire history from the subtree project, produce
153 -only a single commit that contains all the differences you want to
154 -merge, and then merge that new commit into your project.
154 + Instead of merging the entire history from the subtree project, produce
155 + only a single commit that contains all the differences you want to
156 + merge, and then merge that new commit into your project.
157 +
158 Using this option helps to reduce log clutter. People rarely want to see
159 every change that happened between v1.0 and v1.1 of the library they're
@@ -175,56 +177,48 @@ remain intact and can be later split and send upstream to the
177 subproject.
178
179
178 -OPTIONS FOR split
179 ------------------
180 +OPTIONS FOR 'split'
181 +-------------------
182 +These options are only valid for 'split'.
183 +
184 --annotate=<annotation>::
181 - This option is only valid for the split command.
182 -+
183 -When generating synthetic history, add <annotation> as a prefix to each
184 -commit message. Since we're creating new commits with the same commit
185 -message, but possibly different content, from the original commits, this
186 -can help to differentiate them and avoid confusion.
185 + When generating synthetic history, add <annotation> as a prefix to each
186 + commit message. Since we're creating new commits with the same commit
187 + message, but possibly different content, from the original commits, this
188 + can help to differentiate them and avoid confusion.
189 +
190 Whenever you split, you need to use the same <annotation>, or else you
191 don't have a guarantee that the new re-created history will be identical
192 to the old one. That will prevent merging from working correctly. git
191 -subtree tries to make it work anyway, particularly if you use --rejoin,
193 +subtree tries to make it work anyway, particularly if you use '--rejoin',
194 but it may not always be effective.
195
196 -b <branch>::
197 --branch=<branch>::
196 - This option is only valid for the split command.
197 -+
198 -After generating the synthetic history, create a new branch called
199 -<branch> that contains the new history. This is suitable for immediate
200 -pushing upstream. <branch> must not already exist.
198 + After generating the synthetic history, create a new branch called
199 + <branch> that contains the new history. This is suitable for immediate
200 + pushing upstream. <branch> must not already exist.
201
202 --ignore-joins::
203 - This option is only valid for the split command.
204 -+
205 -If you use '--rejoin', git subtree attempts to optimize its history
206 -reconstruction to generate only the new commits since the last
207 -'--rejoin'. '--ignore-join' disables this behaviour, forcing it to
208 -regenerate the entire history. In a large project, this can take a long
209 -time.
203 + If you use '--rejoin', git subtree attempts to optimize its history
204 + reconstruction to generate only the new commits since the last
205 + '--rejoin'. '--ignore-joins' disables this behavior, forcing it to
206 + regenerate the entire history. In a large project, this can take a long
207 + time.
208
209 --onto=<onto>::
212 - This option is only valid for the split command.
213 -+
214 -If your subtree was originally imported using something other than git
215 -subtree, its history may not match what git subtree is expecting. In
216 -that case, you can specify the commit id <onto> that corresponds to the
217 -first revision of the subproject's history that was imported into your
218 -project, and git subtree will attempt to build its history from there.
210 + If your subtree was originally imported using something other than git
211 + subtree, its history may not match what git subtree is expecting. In
212 + that case, you can specify the commit ID <onto> that corresponds to the
213 + first revision of the subproject's history that was imported into your
214 + project, and git subtree will attempt to build its history from there.
215 +
216 If you used 'git subtree add', you should never need this option.
217
218 --rejoin::
223 - This option is only valid for the split command.
224 -+
225 -After splitting, merge the newly created synthetic history back into
226 -your main project. That way, future splits can search only the part of
227 -history that has been added since the most recent --rejoin.
219 + After splitting, merge the newly created synthetic history back into
220 + your main project. That way, future splits can search only the part of
221 + history that has been added since the most recent '--rejoin'.
222 +
223 If your split commits end up merged into the upstream subproject, and
224 then you want to get the latest upstream version, this will allow git's
@@ -240,8 +234,8 @@ split, because you don't want the subproject's history to be part of
234 your project anyway.
235
236
243 -EXAMPLE 1. Add command
244 -----------------------
237 +EXAMPLE 1. 'add' command
238 +------------------------
239 Let's assume that you have a local repository that you would like
240 to add an external vendor library to. In this case we will add the
241 git-subtree repository as a subdirectory of your already existing
@@ -253,15 +247,15 @@ git-extensions repository in ~/git-extensions/:
247 'master' needs to be a valid remote ref and can be a different branch
248 name
249
256 -You can omit the --squash flag, but doing so will increase the number
250 +You can omit the '--squash' flag, but doing so will increase the number
251 of commits that are included in your local repository.
252
253 We now have a ~/git-extensions/git-subtree directory containing code
254 from the master branch of git://github.com/apenwarr/git-subtree.git
255 in our git-extensions repository.
256
263 -EXAMPLE 2. Extract a subtree using commit, merge and pull
264 ----------------------------------------------------------
257 +EXAMPLE 2. Extract a subtree using 'commit', 'merge' and 'pull'
258 +---------------------------------------------------------------
259 Let's use the repository for the git source code as an example.
260 First, get your own copy of the git.git repository:
261
@@ -269,7 +263,7 @@ First, get your own copy of the git.git repository:
263 $ cd test-git
264
265 gitweb (commit 1130ef3) was merged into git as of commit
272 -0a8f4f0, after which it was no longer maintained separately.
266 +0a8f4f0, after which it was no longer maintained separately.
267 But imagine it had been maintained separately, and we wanted to
268 extract git's changes to gitweb since that time, to share with
269 the upstream. You could do this:
@@ -279,14 +273,14 @@ the upstream. You could do this:
273 --branch gitweb-latest
274 $ gitk gitweb-latest
275 $ git push git@github.com:whatever/gitweb.git gitweb-latest:master
282 -
276 +
277 (We use '0a8f4f0^..' because that means "all the changes from
278 0a8f4f0 to the current version, including 0a8f4f0 itself.")
279
280 If gitweb had originally been merged using 'git subtree add' (or
287 -a previous split had already been done with --rejoin specified)
281 +a previous split had already been done with '--rejoin' specified)
282 then you can do all your splits without having to remember any
289 -weird commit ids:
283 +weird commit IDs:
284
285 $ git subtree split --prefix=gitweb --annotate='(split) ' --rejoin \
286 --branch gitweb-latest2
@@ -313,7 +307,7 @@ And fast forward again:
307 $ git subtree merge --prefix=gitweb --squash gitweb-latest
308
309 And notice that your change is still intact:
316 -
310 +
311 $ ls -l gitweb/myfile
312
313 And you can split it out and look at your changes versus
@@ -321,8 +315,8 @@ the standard gitweb:
315
316 git log gitweb-latest..$(git subtree split --prefix=gitweb)
317
324 -EXAMPLE 3. Extract a subtree using branch
325 ------------------------------------------
318 +EXAMPLE 3. Extract a subtree using a branch
319 +-------------------------------------------
320 Suppose you have a source directory with many files and
321 subdirectories, and you want to extract the lib directory to its own
322 git project. Here's a short way to do it:
contrib/subtree/todo
+3 -3
@@ -23,9 +23,9 @@
23
24 "pull" and "merge" commands should fail if you've never merged
25 that --prefix before
26 -
26 +
27 docs should provide an example of "add"
28 -
28 +
29 note that the initial split doesn't *have* to have a commitid
30 specified... that's just an optimization
31
@@ -33,7 +33,7 @@
33 get a misleading "prefix must end with /" message from
34 one of the other git tools that git-subtree calls. Should
35 detect this situation and print the *real* problem.
36 -
36 +
37 "pull --squash" should do fetch-synthesize-merge, but instead just
38 does "pull" directly, which doesn't work at all.
39