Merge branch 'tc/checkout-B'

[thirdparty/git.git] / Documentation / git-checkout.txt

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 7146288ad6b8a2bc8b44513e76d87cdb628827e9..66e570113a077d2c52c4fc3ac09d24a272df5301 100644 (file)
--- a/Documentation/git-checkout.txt
+++ b/Documentation/git-checkout.txt
@@ -9,7 +9,7 @@ SYNOPSIS
 --------
 [verse]
 'git checkout' [-q] [-f] [-m] [<branch>]
-'git checkout' [-q] [-f] [-m] [-b <new_branch>] [<start_point>]
+'git checkout' [-q] [-f] [-m] [[-b|-B|--orphan] <new_branch>] [<start_point>]
 'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...
 'git checkout' --patch [<tree-ish>] [--] [<paths>...]
 
@@ -21,7 +21,7 @@ also update `HEAD` to set the specified branch as the current
 branch.
 
 'git checkout' [<branch>]::
-'git checkout' -b <new branch> [<start point>]::
+'git checkout' -b|-B <new_branch> [<start point>]::
 
        This form switches branches by updating the index, working
        tree, and HEAD to reflect the specified branch.
@@ -31,6 +31,17 @@ were called and then checked out; in this case you can
 use the `--track` or `--no-track` options, which will be passed to
 'git branch'.  As a convenience, `--track` without `-b` implies branch
 creation; see the description of `--track` below.
++
+If `-B` is given, <new_branch> is created if it doesn't exist; otherwise, it
+is reset. This is the transactional equivalent of
++
+------------
+$ git branch -f <branch> [<start point>]
+$ git checkout <branch>
+------------
++
+that is to say, the branch is not reset/created unless "git checkout" is
+successful.
 
 'git checkout' [--patch] [<tree-ish>] [--] <pathspec>...::
 
@@ -75,6 +86,12 @@ entries; instead, unmerged entries are ignored.
        Create a new branch named <new_branch> and start it at
        <start_point>; see linkgit:git-branch[1] for details.
 
+-B::
+       Creates the branch <new_branch> and start it at <start_point>;
+       if it already exists, then reset it to <start_point>. This is
+       equivalent to running "git branch" with "-f"; see
+       linkgit:git-branch[1] for details.
+
 -t::
 --track::
        When creating a new branch, set up "upstream" configuration. See
@@ -98,6 +115,31 @@ explicitly give a name with '-b' in such a case.
        Create the new branch's reflog; see linkgit:git-branch[1] for
        details.
 
+--orphan::
+       Create a new 'orphan' branch, named <new_branch>, started from
+       <start_point> and switch to it.  The first commit made on this
+       new branch will have no parents and it will be the root of a new
+       history totally disconnected from all the other branches and
+       commits.
++
+The index and the working tree are adjusted as if you had previously run
+"git checkout <start_point>".  This allows you to start a new history
+that records a set of paths similar to <start_point> by easily running
+"git commit -a" to make the root commit.
++
+This can be useful when you want to publish the tree from a commit
+without exposing its full history. You might want to do this to publish
+an open source branch of a project whose current tree is "clean", but
+whose full history contains proprietary or otherwise encumbered bits of
+code.
++
+If you want to start a disconnected history that records a set of paths
+that is totally different from the one of <start_point>, then you should
+clear the index and the working tree right after creating the orphan
+branch by running "git rm -rf ." from the top level of the working tree.
+Afterwards you will be ready to prepare your new files, repopulating the
+working tree, by copying them from elsewhere, extracting a tarball, etc.
+
 -m::
 --merge::
        When switching branches,
@@ -238,7 +280,7 @@ the above checkout would fail like this:
 +
 ------------
 $ git checkout mytopic
-fatal: Entry 'frotz' not uptodate. Cannot merge.
+error: You have local changes to 'frotz'; not switching branches.
 ------------
 +
 You can give the `-m` flag to the command, which would try a