#!/bin/sh
-. git-sh-setup || die "Not a git archive"
+
+USAGE='[-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]'
+SUBDIRECTORY_OK=Sometimes
+. git-sh-setup
old=$(git-rev-parse HEAD)
new=
force=
branch=
newbranch=
+merge=
while [ "$#" != "0" ]; do
arg="$1"
shift
die "git checkout: -b needs a branch name"
[ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
die "git checkout: branch $newbranch already exists"
+ git-check-ref-format "heads/$newbranch" ||
+ die "git checkout: we do not like '$newbranch' as a branch name."
;;
"-f")
force=1
;;
+ -m)
+ merge=1
+ ;;
+ --)
+ break
+ ;;
+ -*)
+ usage
+ ;;
*)
- rev=$(git-rev-parse --verify "$arg^0") || exit
- if [ -z "$rev" ]; then
- echo "unknown flag $arg"
- exit 1
- fi
- if [ "$new" ]; then
- echo "Multiple revisions?"
- exit 1
- fi
- new="$rev"
- if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
- branch="$arg"
+ if rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null)
+ then
+ if [ -z "$rev" ]; then
+ echo "unknown flag $arg"
+ exit 1
+ fi
+ new="$rev"
+ if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
+ branch="$arg"
+ fi
+ elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
+ then
+ # checking out selected paths from a tree-ish.
+ new="$rev"
+ branch=
+ else
+ new=
+ branch=
+ set x "$arg" "$@"
+ shift
fi
+ break
;;
esac
done
-[ -z "$new" ] && new=$old
+# The behaviour of the command with and without explicit path
+# parameters is quite different.
+#
+# Without paths, we are checking out everything in the work tree,
+# possibly switching branches. This is the traditional behaviour.
#
+# With paths, we are _never_ switching branch, but checking out
+# the named paths from either index (when no rev is given),
+# or the named tree-ish (when rev is given).
+
+if test "$#" -ge 1
+then
+ hint=
+ if test "$#" -eq 1
+ then
+ hint="
+Did you intend to checkout '$@' which can not be resolved as commit?"
+ fi
+ if test '' != "$newbranch$force$merge"
+ then
+ die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
+ fi
+ if test '' != "$new"
+ then
+ # from a specific tree-ish; note that this is for
+ # rescuing paths and is never meant to remove what
+ # is not in the named tree-ish.
+ git-ls-tree --full-name -r "$new" "$@" |
+ git-update-index --index-info || exit $?
+ fi
+ git-checkout-index -f -u -- "$@"
+ exit $?
+else
+ # Make sure we did not fall back on $arg^{tree} codepath
+ # since we are not checking out from an arbitrary tree-ish,
+ # but switching branches.
+ if test '' != "$new"
+ then
+ git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
+ die "Cannot switch branch to a non-commit."
+ fi
+fi
+
+# We are switching branches and checking out trees, so
+# we *NEED* to be at the toplevel.
+cdup=$(git-rev-parse --show-cdup)
+if test ! -z "$cdup"
+then
+ cd "$cdup"
+fi
+
+[ -z "$new" ] && new=$old
+
# If we don't have an old 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
-#
+
[ -z "$branch$newbranch" ] &&
[ "$new" != "$old" ] &&
- die "git checkout: you need to specify a new branch name"
+ die "git checkout: to checkout the requested commit you need to specify
+ a name for a new branch which is created and switched to"
if [ "$force" ]
then
git-read-tree --reset $new &&
git-checkout-index -q -f -u -a
else
- git-read-tree -m -u $old $new
+ git-update-index --refresh >/dev/null
+ merge_error=$(git-read-tree -m -u $old $new 2>&1) || (
+ case "$merge" in
+ '')
+ echo >&2 "$merge_error"
+ exit 1 ;;
+ esac
+
+ # 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 $new &&
+ git checkout-index -f -u -q -a &&
+ git read-tree -m -u $old $new $work || 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
+
+ # Do not register the cleanly merged paths in the index yet.
+ # this is not a real merge before committing, but just carrying
+ # the working tree changes along.
+ unmerged=`git ls-files -u`
+ git read-tree --reset $new
+ case "$unmerged" in
+ '') ;;
+ *)
+ (
+ z40=0000000000000000000000000000000000000000
+ echo "$unmerged" |
+ sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /"
+ echo "$unmerged"
+ ) | git update-index --index-info
+ ;;
+ esac
+ exit 0
+ )
+ saved_err=$?
+ if test "$saved_err" = 0
+ then
+ test "$new" = "$old" || git diff-index --name-status "$new"
+ fi
+ (exit $saved_err)
fi
#
-# Switch the HEAD pointer to the new branch if it we
+# Switch the HEAD pointer to the new branch if we
# checked out a branch head, and remove any potential
# old MERGE_HEAD's (subsequent commits will clearly not
# be based on them, since we re-set the index)
#
if [ "$?" -eq 0 ]; then
if [ "$newbranch" ]; then
- echo $new > "$GIT_DIR/refs/heads/$newbranch"
+ leading=`expr "refs/heads/$newbranch" : '\(.*\)/'` &&
+ mkdir -p "$GIT_DIR/$leading" &&
+ echo $new >"$GIT_DIR/refs/heads/$newbranch" || exit
branch="$newbranch"
fi
- [ "$branch" ] && ln -sf "refs/heads/$branch" "$GIT_DIR/HEAD"
+ [ "$branch" ] &&
+ GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch"
rm -f "$GIT_DIR/MERGE_HEAD"
else
exit 1