#!/bin/sh
-USAGE='[-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]'
+USAGE='[-
q] [-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]'
SUBDIRECTORY_OK=Sometimes
. git-sh-setup
+require_work_tree
old_name=HEAD
old=$(git-rev-parse --verify $old_name 2>/dev/null)
+oldbranch=$(git-symbolic-ref $old_name 2>/dev/null)
new=
new_name=
force=
branch=
+track=
newbranch=
newbranch_log=
merge=
+quiet=
+LF='
+'
while [ "$#" != "0" ]; do
arg="$1"
shift
die "git checkout: we do not like '$newbranch' as a branch name."
;;
"-l")
- newbranch_log=1
+ newbranch_log=-l
+ ;;
+ "--track"|"--no-track")
+ track="$arg"
;;
"-f")
force=1
-m)
merge=1
;;
+ "-q")
+ quiet=1
+ ;;
--)
break
;;
exit 1
fi
new="$rev"
- new_name="$arg^0"
+ new_name="$arg"
if git-show-ref --verify --quiet -- "refs/heads/$arg"
then
branch="$arg"
esac
done
+case "$newbranch,$track" in
+,--*)
+ die "git checkout: --track and --no-track require -b"
+esac
+
case "$force$merge" in
11)
die "git checkout: -f and -m are incompatible"
# We are switching branches and checking out trees, so
# we *NEED* to be at the toplevel.
-cdup=$(git-rev-parse --show-cdup)
-if test ! -z "$cdup"
-then
- cd "$cdup"
-fi
+cd_to_toplevel
[ -z "$new" ] && new=$old && new_name="$old_name"
-# If we don't have an old branch that we're switching to,
+# If we don't have an existing branch that we're switching to,
# and we don't have a new branch name for the target we
-# are switching to, then we'd better just be checking out
-# what we already had
+# are switching to, then we are detaching our HEAD from any
+# branch. However, if "git checkout HEAD" detaches the HEAD
+# from the current branch, even though that may be logically
+# correct, it feels somewhat funny. More importantly, we do not
+# want "git checkout" nor "git checkout -f" to detach HEAD.
-[ -z "$branch$newbranch" ] &&
- [ "$new" != "$old" ] &&
- die "git checkout: provided reference cannot be checked out directly
+detached=
+detach_warn=
- You need -b to associate a new branch with the wanted checkout. Example:
- git checkout -b <new_branch_name> $arg
-"
+describe_detached_head () {
+ test -n "$quiet" || {
+ printf >&2 "$1 "
+ GIT_PAGER= git log >&2 -1 --pretty=oneline --abbrev-commit "$2"
+ }
+}
+
+if test -z "$branch$newbranch" && test "$new_name" != "$old_name"
+then
+ detached="$new"
+ if test -n "$oldbranch" && test -z "$quiet"
+ then
+ detach_warn="Note: moving to \"$new_name\" which isn't a local branch
+If you want to create a new branch from this checkout, you may do so
+(now or later) by using -b with the checkout command again. Example:
+ git checkout -b <new_branch_name>"
+ fi
+elif test -z "$oldbranch" && test "$new" != "$old"
+then
+ describe_detached_head 'Previous HEAD position was' "$old"
+fi
if [ "X$old" = X ]
then
- echo "warning: You do not appear to currently be on a branch." >&2
- echo "warning: Forcing checkout of $new_name." >&2
+ if test -z "$quiet"
+ then
+ echo >&2 "warning: You appear to be on a branch yet to be born."
+ echo >&2 "warning: Forcing checkout of $new_name."
+ fi
force=1
fi
# Match the index to the working tree, and do a three-way.
git diff-files --name-only | git update-index --remove --stdin &&
work=`git write-tree` &&
- git read-tree --reset -u $new &&
- git read-tree -m -u --aggressive --exclude-per-directory=.gitignore $old $new $work ||
- exit
+ git read-tree --reset -u $new || exit
- if result=`git write-tree 2>/dev/null`
- then
- echo >&2 "Trivially automerged."
- else
- git merge-index -o git-merge-one-file -a
- fi
+ eval GITHEAD_$new='${new_name:-${branch:-$new}}' &&
+ eval GITHEAD_$work=local &&
+ export GITHEAD_$new GITHEAD_$work &&
+ git merge-recursive $old -- $new $work
# Do not register the cleanly merged paths in the index yet.
# this is not a real merge before committing, but just carrying
exit 0
)
saved_err=$?
- if test "$saved_err" = 0
+ if test "$saved_err" = 0 && test -z "$quiet"
then
- test "$new" = "$old" || git diff-index --name-status "$new"
+ git diff-index --name-status "$new"
fi
(exit $saved_err)
fi
#
if [ "$?" -eq 0 ]; then
if [ "$newbranch" ]; then
- if [ "$newbranch_log" ]; then
- mkdir -p $(dirname "$GIT_DIR/logs/refs/heads/$newbranch")
- touch "$GIT_DIR/logs/refs/heads/$newbranch"
- fi
- git-update-ref -m "checkout: Created from $new_name" "refs/heads/$newbranch" $new || exit
+ git-branch $track $newbranch_log "$newbranch" "$new_name" || exit
branch="$newbranch"
fi
- [ "$branch" ] &&
- GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch"
+ if test -n "$branch"
+ then
+ GIT_DIR="$GIT_DIR" git-symbolic-ref -m "checkout: moving to $branch" HEAD "refs/heads/$branch"
+ if test -n "$quiet"
+ then
+ true # nothing
+ elif test "refs/heads/$branch" = "$oldbranch"
+ then
+ echo >&2 "Already on branch \"$branch\""
+ else
+ echo >&2 "Switched to${newbranch:+ a new} branch \"$branch\""
+ fi
+ elif test -n "$detached"
+ then
+ # NEEDSWORK: we would want a command to detach the HEAD
+ # atomically, instead of this handcrafted command sequence.
+ # Perhaps:
+ # git update-ref --detach HEAD $new
+ # or something like that...
+ #
+ git-rev-parse HEAD >"$GIT_DIR/HEAD.new" &&
+ mv "$GIT_DIR/HEAD.new" "$GIT_DIR/HEAD" &&
+ git-update-ref -m "checkout: moving to $arg" HEAD "$detached" ||
+ die "Cannot detach HEAD"
+ if test -n "$detach_warn"
+ then
+ echo >&2 "$detach_warn"
+ fi
+ describe_detached_head 'HEAD is now at' HEAD
+ fi
rm -f "$GIT_DIR/MERGE_HEAD"
else
exit 1