doc: promote "git switch"

The new command "git switch" is added to avoid the confusion of
one-command-do-all "git checkout" for new users. They are also helpful
to avoid ambiguation context.

For these reasons, promote it everywhere possible. This includes
documentation, suggestions/advice from other commands...

The "Checking out files" progress line in unpack-trees.c is also updated
to "Updating files" to be neutral to both git-checkout and git-switch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-branch.txt

@@ -48,7 +48,7 @@ The command's second form creates a new branch head named <branchname>
 which points to the current `HEAD`, or <start-point> if given.
 
 Note that this will create the new branch, but it will not switch the
-working tree to it; use "git checkout <newbranch>" to switch to the
+working tree to it; use "git switch <newbranch>" to switch to the
 new branch.
 
 When a local branch is started off a remote-tracking branch, Git sets up the
@@ -198,7 +198,7 @@ This option is only applicable in non-verbose mode.
 +
 This behavior is the default when the start point is a remote-tracking branch.
 Set the branch.autoSetupMerge configuration variable to `false` if you
-want `git checkout` and `git branch` to always behave as if `--no-track`
+want `git switch`, `git checkout` and `git branch` to always behave as if `--no-track`
 were given. Set it to `always` if you want this behavior when the
 start-point is either a local or remote-tracking branch.
 
@@ -297,7 +297,7 @@ Start development from a known tag::
 $ git clone git://git.kernel.org/pub/scm/.../linux-2.6 my2.6
 $ cd my2.6
 $ git branch my2.6.14 v2.6.14   <1>
-$ git checkout my2.6.14
+$ git switch my2.6.14
 ------------
 +
 <1> This step and the next one could be combined into a single step with
@@ -322,9 +322,9 @@ $ git branch -D test                                    <2>
 NOTES
 -----
 
-If you are creating a branch that you want to checkout immediately, it is
-easier to use the git checkout command with its `-b` option to create
-a branch and check it out with a single command.
+If you are creating a branch that you want to switch to immediately,
+it is easier to use the "git switch" command with its `-c` option to
+do the same thing with a single command.
 
 The options `--contains`, `--no-contains`, `--merged` and `--no-merged`
 serve four related but different purposes:

Documentation/git-check-ref-format.txt

@@ -88,7 +88,8 @@ but it is explicitly forbidden at the beginning of a branch name).
 When run with `--branch` option in a repository, the input is first
 expanded for the ``previous checkout syntax''
 `@{-n}`.  For example, `@{-1}` is a way to refer the last thing that
-was checked out using "git checkout" operation. This option should be
+was checked out using "git switch" or "git checkout" operation.
+This option should be
 used by porcelains to accept this syntax anywhere a branch name is
 expected, so they can act as if you typed the branch name. As an
 exception note that, the ``previous checkout operation'' might result

Documentation/git-format-patch.txt

@@ -421,7 +421,7 @@ One way to test if your MUA is set up correctly is:
 * Apply it:
 
     $ git fetch <project> master:test-apply
-    $ git checkout test-apply
+    $ git switch test-apply
     $ git reset --hard
     $ git am a.patch
 

Documentation/git-merge-base.txt

@@ -149,7 +149,7 @@ instead.
 Discussion on fork-point mode
 -----------------------------
 
-After working on the `topic` branch created with `git checkout -b
+After working on the `topic` branch created with `git switch -c
 topic origin/master`, the history of remote-tracking branch
 `origin/master` may have been rewound and rebuilt, leading to a
 history of this shape:

Documentation/git-rebase.txt

@@ -17,7 +17,7 @@ SYNOPSIS
 DESCRIPTION
 -----------
 If <branch> is specified, 'git rebase' will perform an automatic
-`git checkout <branch>` before doing anything else.  Otherwise
+`git switch <branch>` before doing anything else.  Otherwise
 it remains on the current branch.
 
 If <upstream> is not specified, the upstream configured in

Documentation/git-remote.txt

@@ -230,7 +230,7 @@ $ git branch -r
   staging/master
   staging/staging-linus
   staging/staging-next
-$ git checkout -b staging staging/master
+$ git switch -c staging staging/master
 ...
 ------------
 

Documentation/git-rerere.txt

@@ -91,7 +91,7 @@ For such a test, you need to merge master and topic somehow.
 One way to do it is to pull master into the topic branch:
 
 ------------
-	$ git checkout topic
+	$ git switch topic
 	$ git merge master
 
               o---*---o---+ topic
@@ -113,10 +113,10 @@ the upstream might have been advanced since the test merge `+`,
 in which case the final commit graph would look like this:
 
 ------------
-	$ git checkout topic
+	$ git switch topic
 	$ git merge master
 	$ ... work on both topic and master branches
-	$ git checkout master
+	$ git switch master
 	$ git merge topic
 
               o---*---o---+---o---o topic
@@ -136,11 +136,11 @@ merges, you could blow away the test merge, and keep building on
 top of the tip before the test merge:
 
 ------------
-	$ git checkout topic
+	$ git switch topic
 	$ git merge master
 	$ git reset --hard HEAD^ ;# rewind the test merge
 	$ ... work on both topic and master branches
-	$ git checkout master
+	$ git switch master
 	$ git merge topic
 
               o---*---o-------o---o topic

Documentation/git-reset.txt

@@ -149,9 +149,9 @@ See also the `--amend` option to linkgit:git-commit[1].
 Undo a commit, making it a topic branch::
 +
 ------------
-$ git branch topic/wip     <1>
-$ git reset --hard HEAD~3  <2>
-$ git checkout topic/wip   <3>
+$ git branch topic/wip          <1>
+$ git reset --hard HEAD~3       <2>
+$ git switch topic/wip          <3>
 ------------
 +
 <1> You have made some commits, but realize they were premature
@@ -232,13 +232,13 @@ working tree are not in any shape to be committed yet, but you
 need to get to the other branch for a quick bugfix.
 +
 ------------
-$ git checkout feature ;# you were working in "feature" branch and
-$ work work work       ;# got interrupted
+$ git switch feature  ;# you were working in "feature" branch and
+$ work work work      ;# got interrupted
 $ git commit -a -m "snapshot WIP"                 <1>
-$ git checkout master
+$ git switch master
 $ fix fix fix
 $ git commit ;# commit with real log
-$ git checkout feature
+$ git switch feature
 $ git reset --soft HEAD^ ;# go back to WIP state  <2>
 $ git reset                                       <3>
 ------------
@@ -279,18 +279,18 @@ reset it while keeping the changes in your working tree.
 +
 ------------
 $ git tag start
-$ git checkout -b branch1
+$ git switch -c branch1
 $ edit
 $ git commit ...                            <1>
 $ edit
-$ git checkout -b branch2                   <2>
+$ git switch -c branch2                     <2>
 $ git reset --keep start                    <3>
 ------------
 +
 <1> This commits your first edits in `branch1`.
 <2> In the ideal world, you could have realized that the earlier
     commit did not belong to the new topic when you created and switched
-    to `branch2` (i.e. `git checkout -b branch2 start`), but nobody is
+    to `branch2` (i.e. `git switch -c branch2 start`), but nobody is
     perfect.
 <3> But you can use `reset --keep` to remove the unwanted commit after
     you switched to `branch2`.

Documentation/git-stash.txt

@@ -235,12 +235,12 @@ return to your original branch to make the emergency fix, like this:
 +
 ----------------------------------------------------------------
 # ... hack hack hack ...
-$ git checkout -b my_wip
+$ git switch -c my_wip
 $ git commit -a -m "WIP"
-$ git checkout master
+$ git switch master
 $ edit emergency fix
 $ git commit -a -m "Fix in a hurry"
-$ git checkout my_wip
+$ git switch my_wip
 $ git reset --soft HEAD^
 # ... continue hacking ...
 ----------------------------------------------------------------
@@ -293,7 +293,8 @@ SEE ALSO
 linkgit:git-checkout[1],
 linkgit:git-commit[1],
 linkgit:git-reflog[1],
-linkgit:git-reset[1]
+linkgit:git-reset[1],
+linkgit:git-switch[1]
 
 GIT
 ---

Documentation/gitcore-tutorial.txt

@@ -741,7 +741,7 @@ used earlier, and create a branch in it. You do that by simply just
 saying that you want to check out a new branch:
 
 ------------
-$ git checkout -b mybranch
+$ git switch -c mybranch
 ------------
 
 will create a new branch based at the current `HEAD` position, and switch
@@ -755,7 +755,7 @@ just telling 'git checkout' what the base of the checkout would be.
 In other words, if you have an earlier tag or branch, you'd just do
 
 ------------
-$ git checkout -b mybranch earlier-commit
+$ git switch -c mybranch earlier-commit
 ------------
 
 and it would create the new branch `mybranch` at the earlier commit,
@@ -765,7 +765,7 @@ and check out the state at that time.
 You can always just jump back to your original `master` branch by doing
 
 ------------
-$ git checkout master
+$ git switch master
 ------------
 
 (or any other branch-name, for that matter) and if you forget which
@@ -794,7 +794,7 @@ $ git branch <branchname> [startingpoint]
 
 which will simply _create_ the branch, but will not do anything further.
 You can then later -- once you decide that you want to actually develop
-on that branch -- switch to that branch with a regular 'git checkout'
+on that branch -- switch to that branch with a regular 'git switch'
 with the branchname as the argument.
 
 
@@ -808,7 +808,7 @@ being the same as the original `master` branch, let's make sure we're in
 that branch, and do some work there.
 
 ------------------------------------------------
-$ git checkout mybranch
+$ git switch mybranch
 $ echo "Work, work, work" >>hello
 $ git commit -m "Some work." -i hello
 ------------------------------------------------
@@ -825,7 +825,7 @@ does some work in the original branch, and simulate that by going back
 to the master branch, and editing the same file differently there:
 
 ------------
-$ git checkout master
+$ git switch master
 ------------
 
 Here, take a moment to look at the contents of `hello`, and notice how they
@@ -958,7 +958,7 @@ to the `master` branch. Let's go back to `mybranch`, and run
 'git merge' to get the "upstream changes" back to your branch.
 
 ------------
-$ git checkout mybranch
+$ git switch mybranch
 $ git merge -m "Merge upstream changes." master
 ------------
 
@@ -1133,9 +1133,8 @@ Remember, before running 'git merge', our `master` head was at
 work." commit.
 
 ------------
-$ git checkout mybranch
-$ git reset --hard master^2
-$ git checkout master
+$ git switch -C mybranch master^2
+$ git switch master
 $ git reset --hard master^
 ------------
 

Documentation/giteveryday.txt

@@ -41,7 +41,7 @@ following commands.
 
   * linkgit:git-log[1] to see what happened.
 
-  * linkgit:git-checkout[1] and linkgit:git-branch[1] to switch
+  * linkgit:git-switch[1] and linkgit:git-branch[1] to switch
     branches.
 
   * linkgit:git-add[1] to manage the index file.
@@ -80,7 +80,7 @@ $ git tag v2.43 <2>
 Create a topic branch and develop.::
 +
 ------------
-$ git checkout -b alsa-audio <1>
+$ git switch -c alsa-audio <1>
 $ edit/compile/test
 $ git checkout -- curses/ux_audio_oss.c <2>
 $ git add curses/ux_audio_alsa.c <3>
@@ -90,7 +90,7 @@ $ git commit -a -s <5>
 $ edit/compile/test
 $ git diff HEAD^ <6>
 $ git commit -a --amend <7>
-$ git checkout master <8>
+$ git switch master <8>
 $ git merge alsa-audio <9>
 $ git log --since='3 days ago' <10>
 $ git log v2.43.. curses/ <11>
@@ -148,11 +148,11 @@ Clone the upstream and work on it.  Feed changes to upstream.::
 ------------
 $ git clone git://git.kernel.org/pub/scm/.../torvalds/linux-2.6 my2.6
 $ cd my2.6
-$ git checkout -b mine master <1>
+$ git switch -c mine master <1>
 $ edit/compile/test; git commit -a -s <2>
 $ git format-patch master <3>
 $ git send-email --to="person <email@example.com>" 00*.patch <4>
-$ git checkout master <5>
+$ git switch master <5>
 $ git pull <6>
 $ git log -p ORIG_HEAD.. arch/i386 include/asm-i386 <7>
 $ git ls-remote --heads http://git.kernel.org/.../jgarzik/libata-dev.git <8>
@@ -194,7 +194,7 @@ satellite$ edit/compile/test/commit
 satellite$ git push origin <4>
 
 mothership$ cd frotz
-mothership$ git checkout master
+mothership$ git switch master
 mothership$ git merge satellite/master <5>
 ------------
 +
@@ -216,7 +216,7 @@ machine into the master branch.
 Branch off of a specific tag.::
 +
 ------------
-$ git checkout -b private2.6.14 v2.6.14 <1>
+$ git switch -c private2.6.14 v2.6.14 <1>
 $ edit/compile/test; git commit -a
 $ git checkout master
 $ git cherry-pick v2.6.14..private2.6.14 <2>
@@ -274,14 +274,14 @@ $ mailx <3>
 & s 2 3 4 5 ./+to-apply
 & s 7 8 ./+hold-linus
 & q
-$ git checkout -b topic/one master
+$ git switch -c topic/one master
 $ git am -3 -i -s ./+to-apply <4>
 $ compile/test
-$ git checkout -b hold/linus && git am -3 -i -s ./+hold-linus <5>
-$ git checkout topic/one && git rebase master <6>
-$ git checkout pu && git reset --hard next <7>
+$ git switch -c hold/linus && git am -3 -i -s ./+hold-linus <5>
+$ git switch topic/one && git rebase master <6>
+$ git switch -C pu next <7>
 $ git merge topic/one topic/two && git merge hold/linus <8>
-$ git checkout maint
+$ git switch maint
 $ git cherry-pick master~4 <9>
 $ compile/test
 $ git tag -s -m "GIT 0.99.9x" v0.99.9x <10>

Documentation/gittutorial.txt

@@ -207,7 +207,7 @@ automatically.  The asterisk marks the branch you are currently on;
 type
 
 ------------------------------------------------
-$ git checkout experimental
+$ git switch experimental
 ------------------------------------------------
 
 to switch to the experimental branch.  Now edit a file, commit the
@@ -216,7 +216,7 @@ change, and switch back to the master branch:
 ------------------------------------------------
 (edit file)
 $ git commit -a
-$ git checkout master
+$ git switch master
 ------------------------------------------------
 
 Check that the change you made is no longer visible, since it was

Documentation/gitworkflows.txt

@@ -301,8 +301,7 @@ topics on 'next':
 .Rewind and rebuild next
 [caption="Recipe: "]
 =====================================
-* `git checkout next`
-* `git reset --hard master`
+* `git switch -C next master`
 * `git merge ai/topic_in_next1`
 * `git merge ai/topic_in_next2`
 * ...

Documentation/revisions.txt

@@ -115,7 +115,7 @@ Here's an example to make it more clear:
 ------------------------------
 $ git config push.default current
 $ git config remote.pushdefault myfork
-$ git checkout -b mybranch origin/master
+$ git switch -c mybranch origin/master
 
 $ git rev-parse --symbolic-full-name @{upstream}
 refs/remotes/origin/master