Do not fail on hierarchical branch names.
[git] / git-checkout.sh
1 #!/bin/sh
2 . git-sh-setup || die "Not a git archive"
3
4 usage () {
5     die "usage: git checkout [-f] [-b <new_branch>] [<branch>] [<paths>...]"
6 }
7
8 old=$(git-rev-parse HEAD)
9 new=
10 force=
11 branch=
12 newbranch=
13 while [ "$#" != "0" ]; do
14     arg="$1"
15     shift
16     case "$arg" in
17         "-b")
18                 newbranch="$1"
19                 shift
20                 [ -z "$newbranch" ] &&
21                         die "git checkout: -b needs a branch name"
22                 [ -e "$GIT_DIR/refs/heads/$newbranch" ] &&
23                         die "git checkout: branch $newbranch already exists"
24                 git-check-ref-format "heads/$newbranch" ||
25                         die "we do not like '$newbranch' as a branch name."
26                 ;;
27         "-f")
28                 force=1
29                 ;;
30         --)
31                 break
32                 ;;
33         -*)
34                 usage
35                 ;;
36         *)
37                 if rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null)
38                 then
39                         if [ -z "$rev" ]; then
40                                 echo "unknown flag $arg"
41                                 exit 1
42                         fi
43                         new="$rev"
44                         if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
45                                 branch="$arg"
46                         fi
47                 elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
48                 then
49                         # checking out selected paths from a tree-ish.
50                         new="$rev"
51                         branch=
52                 else
53                         new=
54                         branch=
55                         set x "$arg" "$@"
56                         shift
57                 fi
58                 break
59                 ;;
60     esac
61 done
62
63 # The behaviour of the command with and without explicit path
64 # parameters is quite different.
65 #
66 # Without paths, we are checking out everything in the work tree,
67 # possibly switching branches.  This is the traditional behaviour.
68 #
69 # With paths, we are _never_ switching branch, but checking out
70 # the named paths from either index (when no rev is given),
71 # or the named tree-ish (when rev is given).
72
73 if test "$#" -ge 1
74 then
75         if test '' != "$newbranch$force"
76         then
77                 die "updating paths and switching branches or forcing are incompatible."
78         fi
79         if test '' != "$new"
80         then
81                 # from a specific tree-ish; note that this is for
82                 # rescuing paths and is never meant to remove what
83                 # is not in the named tree-ish.
84                 git-ls-tree -r "$new" "$@" |
85                 sed -ne 's/^\([0-7]*\) blob \(.*\)$/\1 \2/p' |
86                 git-update-index --index-info || exit $?
87         fi
88         git-checkout-index -f -u -- "$@"
89         exit $?
90 else
91         # Make sure we did not fall back on $arg^{tree} codepath
92         # since we are not checking out from an arbitrary tree-ish,
93         # but switching branches.
94         if test '' != "$new"
95         then
96                 git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
97                 die "Cannot switch branch to a non-commit."
98         fi
99 fi
100
101 [ -z "$new" ] && new=$old
102
103 # If we don't have an old branch that we're switching to,
104 # and we don't have a new branch name for the target we
105 # are switching to, then we'd better just be checking out
106 # what we already had
107
108 [ -z "$branch$newbranch" ] &&
109         [ "$new" != "$old" ] &&
110         die "git checkout: you need to specify a new branch name"
111
112 if [ "$force" ]
113 then
114     git-read-tree --reset $new &&
115         git-checkout-index -q -f -u -a
116 else
117     git-update-index --refresh >/dev/null
118     git-read-tree -m -u $old $new
119 fi
120
121
122 # Switch the HEAD pointer to the new branch if it we
123 # checked out a branch head, and remove any potential
124 # old MERGE_HEAD's (subsequent commits will clearly not
125 # be based on them, since we re-set the index)
126 #
127 if [ "$?" -eq 0 ]; then
128         if [ "$newbranch" ]; then
129                 leading=`expr "refs/heads/$newbranch" : '\(.*\)/'` &&
130                 mkdir -p "$GIT_DIR/$leading" &&
131                 echo $new >"$GIT_DIR/refs/heads/$newbranch" || exit
132                 branch="$newbranch"
133         fi
134         [ "$branch" ] &&
135         GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch"
136         rm -f "$GIT_DIR/MERGE_HEAD"
137 else
138         exit 1
139 fi