fetch.c: do not call process_tree() from process_tree().
[git/git.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
7 old=$(git-rev-parse HEAD)
8 new=
9 force=
10 branch=
11 newbranch=
12 merge=
13 while [ "$#" != "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 "git checkout: we do not like '$newbranch' as a branch name."
26 ;;
27 "-f")
28 force=1
29 ;;
30 -m)
31 merge=1
32 ;;
33 --)
34 break
35 ;;
36 -*)
37 usage
38 ;;
39 *)
40 if rev=$(git-rev-parse --verify "$arg^0" 2>/dev/null)
41 then
42 if [ -z "$rev" ]; then
43 echo "unknown flag $arg"
44 exit 1
45 fi
46 new="$rev"
47 if [ -f "$GIT_DIR/refs/heads/$arg" ]; then
48 branch="$arg"
49 fi
50 elif rev=$(git-rev-parse --verify "$arg^{tree}" 2>/dev/null)
51 then
52 # checking out selected paths from a tree-ish.
53 new="$rev"
54 branch=
55 else
56 new=
57 branch=
58 set x "$arg" "$@"
59 shift
60 fi
61 break
62 ;;
63 esac
64 done
65
66 # The behaviour of the command with and without explicit path
67 # parameters is quite different.
68 #
69 # Without paths, we are checking out everything in the work tree,
70 # possibly switching branches. This is the traditional behaviour.
71 #
72 # With paths, we are _never_ switching branch, but checking out
73 # the named paths from either index (when no rev is given),
74 # or the named tree-ish (when rev is given).
75
76 if test "$#" -ge 1
77 then
78 hint=
79 if test "$#" -eq 1
80 then
81 hint="
82 Did you intend to checkout '$@' which can not be resolved as commit?"
83 fi
84 if test '' != "$newbranch$force$merge"
85 then
86 die "git checkout: updating paths is incompatible with switching branches/forcing$hint"
87 fi
88 if test '' != "$new"
89 then
90 # from a specific tree-ish; note that this is for
91 # rescuing paths and is never meant to remove what
92 # is not in the named tree-ish.
93 git-ls-tree --full-name -r "$new" "$@" |
94 git-update-index --index-info || exit $?
95 fi
96 git-checkout-index -f -u -- "$@"
97 exit $?
98 else
99 # Make sure we did not fall back on $arg^{tree} codepath
100 # since we are not checking out from an arbitrary tree-ish,
101 # but switching branches.
102 if test '' != "$new"
103 then
104 git-rev-parse --verify "$new^{commit}" >/dev/null 2>&1 ||
105 die "Cannot switch branch to a non-commit."
106 fi
107 fi
108
109 # We are switching branches and checking out trees, so
110 # we *NEED* to be at the toplevel.
111 cdup=$(git-rev-parse --show-cdup)
112 if test ! -z "$cdup"
113 then
114 cd "$cdup"
115 fi
116
117 [ -z "$new" ] && new=$old
118
119 # If we don't have an old branch that we're switching to,
120 # and we don't have a new branch name for the target we
121 # are switching to, then we'd better just be checking out
122 # what we already had
123
124 [ -z "$branch$newbranch" ] &&
125 [ "$new" != "$old" ] &&
126 die "git checkout: to checkout the requested commit you need to specify
127 a name for a new branch which is created and switched to"
128
129 if [ "$force" ]
130 then
131 git-read-tree --reset $new &&
132 git-checkout-index -q -f -u -a
133 else
134 git-update-index --refresh >/dev/null
135 merge_error=$(git-read-tree -m -u $old $new 2>&1) || (
136 case "$merge" in
137 '')
138 echo >&2 "$merge_error"
139 exit 1 ;;
140 esac
141
142 # Match the index to the working tree, and do a three-way.
143 git diff-files --name-only | git update-index --remove --stdin &&
144 work=`git write-tree` &&
145 git read-tree --reset $new &&
146 git checkout-index -f -u -q -a &&
147 git read-tree -m -u --aggressive $old $new $work || exit
148
149 if result=`git write-tree 2>/dev/null`
150 then
151 echo >&2 "Trivially automerged."
152 else
153 git merge-index -o git-merge-one-file -a
154 fi
155
156 # Do not register the cleanly merged paths in the index yet.
157 # this is not a real merge before committing, but just carrying
158 # the working tree changes along.
159 unmerged=`git ls-files -u`
160 git read-tree --reset $new
161 case "$unmerged" in
162 '') ;;
163 *)
164 (
165 z40=0000000000000000000000000000000000000000
166 echo "$unmerged" |
167 sed -e 's/^[0-7]* [0-9a-f]* /'"0 $z40 /"
168 echo "$unmerged"
169 ) | git update-index --index-info
170 ;;
171 esac
172 exit 0
173 )
174 saved_err=$?
175 if test "$saved_err" = 0
176 then
177 test "$new" = "$old" || git diff-index --name-status "$new"
178 fi
179 (exit $saved_err)
180 fi
181
182 #
183 # Switch the HEAD pointer to the new branch if we
184 # checked out a branch head, and remove any potential
185 # old MERGE_HEAD's (subsequent commits will clearly not
186 # be based on them, since we re-set the index)
187 #
188 if [ "$?" -eq 0 ]; then
189 if [ "$newbranch" ]; then
190 leading=`expr "refs/heads/$newbranch" : '\(.*\)/'` &&
191 mkdir -p "$GIT_DIR/$leading" &&
192 echo $new >"$GIT_DIR/refs/heads/$newbranch" || exit
193 branch="$newbranch"
194 fi
195 [ "$branch" ] &&
196 GIT_DIR="$GIT_DIR" git-symbolic-ref HEAD "refs/heads/$branch"
197 rm -f "$GIT_DIR/MERGE_HEAD"
198 else
199 exit 1
200 fi