git-svn: fix tests to work with older svn
[git] / git-checkout.sh
1 #!/bin/sh
2
3 USAGE='[-f] [-b <new_branch>] [-m] [<branch>] [<paths>...]'
4 SUBDIRECTORY_OK=Sometimes
5 . git-sh-setup
6 require_work_tree
7
8 old_name=HEAD
9 old=$(git-rev-parse --verify $old_name 2>/dev/null)
10 oldbranch=$(git-symbolic-ref $old_name 2>/dev/null)
11 new=
12 new_name=
13 force=
14 branch=
15 newbranch=
16 newbranch_log=
17 merge=
18 LF='
19 '
20 while [ "$#" != "0" ]; do
21     arg="$1"
22     shift
23     case "$arg" in
24         "-b")
25                 newbranch="$1"
26                 shift
27                 [ -z "$newbranch" ] &&
28                         die "git checkout: -b needs a branch name"
29                 git-show-ref --verify --quiet -- "refs/heads/$newbranch" &&
30                         die "git checkout: branch $newbranch already exists"
31                 git-check-ref-format "heads/$newbranch" ||
32                         die "git checkout: we do not like '$newbranch' as a branch name."
33                 ;;
34         "-l")
35                 newbranch_log=1
36                 ;;
37         "-f")
38                 force=1
39                 ;;
40         -m)
41                 merge=1
42                 ;;
43         --)
44                 break
45                 ;;
46         -*)
47                 usage
48                 ;;
49         *)
50                 if rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null)
51                 then
52                         if [ -z "$rev" ]; then
53                                 echo "unknown flag $arg"
54                                 exit 1
55                         fi
56                         new="$rev"
57                         new_name="$arg"
58                         if git-show-ref --verify --quiet -- "refs/heads/$arg"
59                         then
60                                 branch="$arg"
61                         fi
62                 elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
63                 then
64                         # checking out selected paths from a tree-ish.
65                         new="$rev"
66                         new_name="$arg^{tree}"
67                         branch=
68                 else
69                         new=
70                         new_name=
71                         branch=
72                         set x "$arg" "$@"
73                         shift
74                 fi
75                 case "$1" in
76                 --)
77                         shift ;;
78                 esac
79                 break
80                 ;;
81     esac
82 done
83
84 case "$force$merge" in
85 11)
86         die "git checkout: -f and -m are incompatible"
87 esac
88
89 # The behaviour of the command with and without explicit path
90 # parameters is quite different.
91 #
92 # Without paths, we are checking out everything in the work tree,
93 # possibly switching branches.  This is the traditional behaviour.
94 #
95 # With paths, we are _never_ switching branch, but checking out
96 # the named paths from either index (when no rev is given),
97 # or the named tree-ish (when rev is given).
98
99 if test "$#" -ge 1
100 then
101         hint=
102         if test "$#" -eq 1
103         then
104                 hint="
105 Did you intend to checkout '$@' which can not be resolved as commit?"
106         fi
107         if test '' != "$newbranch$force$merge"
108         then
109                 die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
110         fi
111         if test '' != "$new"
112         then
113                 # from a specific tree-ish; note that this is for
114                 # rescuing paths and is never meant to remove what
115                 # is not in the named tree-ish.
116                 git-ls-tree --full-name -r "$new" "$@" |
117                 git-update-index --index-info || exit $?
118         fi
119
120         # Make sure the request is about existing paths.
121         git-ls-files --error-unmatch -- "$@" >/dev/null || exit
122         git-ls-files -- "$@" |
123         git-checkout-index -f -u --stdin
124         exit $?
125 else
126         # Make sure we did not fall back on $arg^{tree} codepath
127         # since we are not checking out from an arbitrary tree-ish,
128         # but switching branches.
129         if test '' != "$new"
130         then
131                 git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
132                 die "Cannot switch branch to a non-commit."
133         fi
134 fi
135
136 # We are switching branches and checking out trees, so
137 # we *NEED* to be at the toplevel.
138 cdup=$(git-rev-parse --show-cdup)
139 if test ! -z "$cdup"
140 then
141         cd "$cdup"
142 fi
143
144 [ -z "$new" ] && new=$old && new_name="$old_name"
145
146 # If we don't have an existing branch that we're switching to,
147 # and we don't have a new branch name for the target we
148 # are switching to, then we are detaching our HEAD from any
149 # branch.  However, if "git checkout HEAD" detaches the HEAD
150 # from the current branch, even though that may be logically
151 # correct, it feels somewhat funny.  More importantly, we do not
152 # want "git checkout" nor "git checkout -f" to detach HEAD.
153
154 detached=
155 detach_warn=
156
157 if test -z "$branch$newbranch" && test "$new" != "$old"
158 then
159         detached="$new"
160         if test -n "$oldbranch"
161         then
162                 detach_warn="warning: you are not on ANY branch anymore.
163 If you meant to create a new branch from the commit, you need -b to
164 associate a new branch with the wanted checkout.  Example:
165   git checkout -b <new_branch_name> $arg"
166         fi
167 elif test -z "$oldbranch" && test -n "$branch"
168 then
169         # Coming back...
170         if test -z "$force"
171         then
172                 git show-ref -d -s | grep "$old" >/dev/null || {
173                         echo >&2 \
174 "You are not on any branch and switching to branch '$new_name'
175 may lose your changes.  At this point, you can do one of two things:
176  (1) Decide it is Ok and say 'git checkout -f $new_name';
177  (2) Start a new branch from the current commit, by saying
178      'git checkout -b <branch-name>'.
179 Leaving your HEAD detached; not switching to branch '$new_name'."
180                         exit 1;
181                 }
182         fi
183 fi
184
185 if [ "X$old" = X ]
186 then
187         echo >&2 "warning: You appear to be on a branch yet to be born."
188         echo >&2 "warning: Forcing checkout of $new_name."
189         force=1
190 fi
191
192 if [ "$force" ]
193 then
194     git-read-tree --reset -u $new
195 else
196     git-update-index --refresh >/dev/null
197     merge_error=$(git-read-tree -m -u --exclude-per-directory=.gitignore $old $new 2>&1) || (
198         case "$merge" in
199         '')
200                 echo >&2 "$merge_error"
201                 exit 1 ;;
202         esac
203
204         # Match the index to the working tree, and do a three-way.
205         git diff-files --name-only | git update-index --remove --stdin &&
206         work=`git write-tree` &&
207         git read-tree --reset -u $new &&
208         git read-tree -m -u --aggressive --exclude-per-directory=.gitignore $old $new $work ||
209         exit
210
211         if result=`git write-tree 2>/dev/null`
212         then
213             echo >&2 "Trivially automerged."
214         else
215             git merge-index -o git-merge-one-file -a
216         fi
217
218         # Do not register the cleanly merged paths in the index yet.
219         # this is not a real merge before committing, but just carrying
220         # the working tree changes along.
221         unmerged=`git ls-files -u`
222         git read-tree --reset $new
223         case "$unmerged" in
224         '')     ;;
225         *)
226                 (
227                         z40=0000000000000000000000000000000000000000
228                         echo "$unmerged" |
229                         sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /"
230                         echo "$unmerged"
231                 ) | git update-index --index-info
232                 ;;
233         esac
234         exit 0
235     )
236     saved_err=$?
237     if test "$saved_err" = 0
238     then
239         test "$new" = "$old" || git diff-index --name-status "$new"
240     fi
241     (exit $saved_err)
242 fi
243
244
245 # Switch the HEAD pointer to the new branch if we
246 # checked out a branch head, and remove any potential
247 # old MERGE_HEAD's (subsequent commits will clearly not
248 # be based on them, since we re-set the index)
249 #
250 if [ "$?" -eq 0 ]; then
251         if [ "$newbranch" ]; then
252                 if [ "$newbranch_log" ]; then
253                         mkdir -p $(dirname "$GIT_DIR/logs/refs/heads/$newbranch")
254                         touch "$GIT_DIR/logs/refs/heads/$newbranch"
255                 fi
256                 git-update-ref -m "checkout: Created from $new_name" "refs/heads/$newbranch" $new || exit
257                 branch="$newbranch"
258         fi
259         if test -n "$branch"
260         then
261                 GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch"
262         elif test -n "$detached"
263         then
264                 # NEEDSWORK: we would want a command to detach the HEAD
265                 # atomically, instead of this handcrafted command sequence.
266                 # Perhaps:
267                 #       git update-ref --detach HEAD $new
268                 # or something like that...
269                 #
270                 echo "$detached" >"$GIT_DIR/HEAD.new" &&
271                 mv "$GIT_DIR/HEAD.new" "$GIT_DIR/HEAD" ||
272                         die "Cannot detach HEAD"
273                 if test -n "$detach_warn"
274                 then
275                         echo >&2 "$detach_warn"
276                 fi
277         fi
278         rm -f "$GIT_DIR/MERGE_HEAD"
279 else
280         exit 1
281 fi