Merge branch 'tc/checkout-B'

* tc/checkout-B:
  builtin/checkout: handle -B from detached HEAD correctly
  builtin/checkout: learn -B
  builtin/checkout: reword hint for -b
  add tests for checkout -b

1 files changed, 19 insertions, 2 deletions

diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
index 1bacd2e104..66e570113a 100644
--- 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|--orphan] <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