Code

builtin-mailinfo.c infrastrcture changes
[git.git] / git-checkout.sh
1 #!/bin/sh
3 USAGE='[-q] [-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]'
4 SUBDIRECTORY_OK=Sometimes
5 . git-sh-setup
6 require_work_tree
8 old_name=HEAD
9 old=$(git-rev-parse --verify $old_name 2>/dev/null)
10 oldbranch=$(git-symbolic-ref $old_name 2>/dev/null)
11 new=
12 new_name=
13 force=
14 branch=
15 newbranch=
16 newbranch_log=
17 merge=
18 quiet=
19 LF='
20 '
21 while [ "$#" != "0" ]; do
22     arg="$1"
23     shift
24     case "$arg" in
25         "-b")
26                 newbranch="$1"
27                 shift
28                 [ -z "$newbranch" ] &&
29                         die "git checkout: -b needs a branch name"
30                 git-show-ref --verify --quiet -- "refs/heads/$newbranch" &&
31                         die "git checkout: branch $newbranch already exists"
32                 git-check-ref-format "heads/$newbranch" ||
33                         die "git checkout: we do not like '$newbranch' as a branch name."
34                 ;;
35         "-l")
36                 newbranch_log=1
37                 ;;
38         "-f")
39                 force=1
40                 ;;
41         -m)
42                 merge=1
43                 ;;
44         "-q")
45                 quiet=1
46                 ;;
47         --)
48                 break
49                 ;;
50         -*)
51                 usage
52                 ;;
53         *)
54                 if rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null)
55                 then
56                         if [ -z "$rev" ]; then
57                                 echo "unknown flag $arg"
58                                 exit 1
59                         fi
60                         new="$rev"
61                         new_name="$arg"
62                         if git-show-ref --verify --quiet -- "refs/heads/$arg"
63                         then
64                                 branch="$arg"
65                         fi
66                 elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
67                 then
68                         # checking out selected paths from a tree-ish.
69                         new="$rev"
70                         new_name="$arg^{tree}"
71                         branch=
72                 else
73                         new=
74                         new_name=
75                         branch=
76                         set x "$arg" "$@"
77                         shift
78                 fi
79                 case "$1" in
80                 --)
81                         shift ;;
82                 esac
83                 break
84                 ;;
85     esac
86 done
88 case "$force$merge" in
89 11)
90         die "git checkout: -f and -m are incompatible"
91 esac
93 # The behaviour of the command with and without explicit path
94 # parameters is quite different.
95 #
96 # Without paths, we are checking out everything in the work tree,
97 # possibly switching branches.  This is the traditional behaviour.
98 #
99 # With paths, we are _never_ switching branch, but checking out
100 # the named paths from either index (when no rev is given),
101 # or the named tree-ish (when rev is given).
103 if test "$#" -ge 1
104 then
105         hint=
106         if test "$#" -eq 1
107         then
108                 hint="
109 Did you intend to checkout '$@' which can not be resolved as commit?"
110         fi
111         if test '' != "$newbranch$force$merge"
112         then
113                 die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
114         fi
115         if test '' != "$new"
116         then
117                 # from a specific tree-ish; note that this is for
118                 # rescuing paths and is never meant to remove what
119                 # is not in the named tree-ish.
120                 git-ls-tree --full-name -r "$new" "$@" |
121                 git-update-index --index-info || exit $?
122         fi
124         # Make sure the request is about existing paths.
125         git-ls-files --error-unmatch -- "$@" >/dev/null || exit
126         git-ls-files -- "$@" |
127         git-checkout-index -f -u --stdin
128         exit $?
129 else
130         # Make sure we did not fall back on $arg^{tree} codepath
131         # since we are not checking out from an arbitrary tree-ish,
132         # but switching branches.
133         if test '' != "$new"
134         then
135                 git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
136                 die "Cannot switch branch to a non-commit."
137         fi
138 fi
140 # We are switching branches and checking out trees, so
141 # we *NEED* to be at the toplevel.
142 cd_to_toplevel
144 [ -z "$new" ] && new=$old && new_name="$old_name"
146 # If we don't have an existing branch that we're switching to,
147 # and we don't have a new branch name for the target we
148 # are switching to, then we are detaching our HEAD from any
149 # branch.  However, if "git checkout HEAD" detaches the HEAD
150 # from the current branch, even though that may be logically
151 # correct, it feels somewhat funny.  More importantly, we do not
152 # want "git checkout" nor "git checkout -f" to detach HEAD.
154 detached=
155 detach_warn=
157 if test -z "$branch$newbranch" && test "$new" != "$old"
158 then
159         detached="$new"
160         if test -n "$oldbranch" && test -z "$quiet"
161         then
162                 detach_warn="Note: moving to \"$new_name\" which isn't a local branch
163 If you want to create a new branch from this checkout, you may do so
164 (now or later) by using -b with the checkout command again. Example:
165   git checkout -b <new_branch_name>"
166         fi
167 elif test -z "$oldbranch" && test -z "$quiet"
168 then
169         echo >&2 "Previous HEAD position was $old"
170 fi
172 if [ "X$old" = X ]
173 then
174         if test -z "$quiet"
175         then
176                 echo >&2 "warning: You appear to be on a branch yet to be born."
177                 echo >&2 "warning: Forcing checkout of $new_name."
178         fi
179         force=1
180 fi
182 if [ "$force" ]
183 then
184     git-read-tree --reset -u $new
185 else
186     git-update-index --refresh >/dev/null
187     merge_error=$(git-read-tree -m -u --exclude-per-directory=.gitignore $old $new 2>&1) || (
188         case "$merge" in
189         '')
190                 echo >&2 "$merge_error"
191                 exit 1 ;;
192         esac
194         # Match the index to the working tree, and do a three-way.
195         git diff-files --name-only | git update-index --remove --stdin &&
196         work=`git write-tree` &&
197         git read-tree --reset -u $new || exit
199         eval GITHEAD_$new=${new_name:-${branch:-$new}} &&
200         eval GITHEAD_$work=local &&
201         export GITHEAD_$new GITHEAD_$work &&
202         git merge-recursive $old -- $new $work
204         # Do not register the cleanly merged paths in the index yet.
205         # this is not a real merge before committing, but just carrying
206         # the working tree changes along.
207         unmerged=`git ls-files -u`
208         git read-tree --reset $new
209         case "$unmerged" in
210         '')     ;;
211         *)
212                 (
213                         z40=0000000000000000000000000000000000000000
214                         echo "$unmerged" |
215                         sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /"
216                         echo "$unmerged"
217                 ) | git update-index --index-info
218                 ;;
219         esac
220         exit 0
221     )
222     saved_err=$?
223     if test "$saved_err" = 0 && test -z "$quiet"
224     then
225         git diff-index --name-status "$new"
226     fi
227     (exit $saved_err)
228 fi
230
231 # Switch the HEAD pointer to the new branch if we
232 # checked out a branch head, and remove any potential
233 # old MERGE_HEAD's (subsequent commits will clearly not
234 # be based on them, since we re-set the index)
236 if [ "$?" -eq 0 ]; then
237         if [ "$newbranch" ]; then
238                 if [ "$newbranch_log" ]; then
239                         mkdir -p $(dirname "$GIT_DIR/logs/refs/heads/$newbranch")
240                         touch "$GIT_DIR/logs/refs/heads/$newbranch"
241                 fi
242                 git-update-ref -m "checkout: Created from $new_name" "refs/heads/$newbranch" $new || exit
243                 branch="$newbranch"
244         fi
245         if test -n "$branch"
246         then
247                 GIT_DIR="$GIT_DIR" git-symbolic-ref -m "checkout: moving to $branch" HEAD "refs/heads/$branch"
248                 if test -z "$quiet"
249                 then
250                         echo >&2 "Switched to${newbranch:+ a new} branch \"$branch\""
251                 fi
252         elif test -n "$detached"
253         then
254                 # NEEDSWORK: we would want a command to detach the HEAD
255                 # atomically, instead of this handcrafted command sequence.
256                 # Perhaps:
257                 #       git update-ref --detach HEAD $new
258                 # or something like that...
259                 #
260                 git-rev-parse HEAD >"$GIT_DIR/HEAD.new" &&
261                 mv "$GIT_DIR/HEAD.new" "$GIT_DIR/HEAD" &&
262                 git-update-ref -m "checkout: moving to $arg" HEAD "$detached" ||
263                         die "Cannot detach HEAD"
264                 if test -n "$detach_warn"
265                 then
266                         echo >&2 "$detach_warn"
267                 fi
268         fi
269         rm -f "$GIT_DIR/MERGE_HEAD"
270 else
271         exit 1
272 fi