Merge branch 'maint'
[git] / git-filter-branch.sh
1 #!/bin/sh
2 #
3 # Rewrite revision history
4 # Copyright (c) Petr Baudis, 2006
5 # Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
6 #
7 # Lets you rewrite the revision history of the current branch, creating
8 # a new branch. You can specify a number of filters to modify the commits,
9 # files and trees.
10
11 set -e
12
13 USAGE="git-filter-branch [-d TEMPDIR] [FILTERS] DESTBRANCH [REV-RANGE]"
14 . git-sh-setup
15
16 warn () {
17         echo "$*" >&2
18 }
19
20 map()
21 {
22         # if it was not rewritten, take the original
23         if test -r "$workdir/../map/$1"
24         then
25                 cat "$workdir/../map/$1"
26         else
27                 echo "$1"
28         fi
29 }
30
31 # override die(): this version puts in an extra line break, so that
32 # the progress is still visible
33
34 die()
35 {
36         echo >&2
37         echo "$*" >&2
38         exit 1
39 }
40
41 # When piped a commit, output a script to set the ident of either
42 # "author" or "committer
43
44 set_ident () {
45         lid="$(echo "$1" | tr "A-Z" "a-z")"
46         uid="$(echo "$1" | tr "a-z" "A-Z")"
47         pick_id_script='
48                 /^'$lid' /{
49                         s/'\''/'\''\\'\'\''/g
50                         h
51                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
52                         s/'\''/'\''\'\'\''/g
53                         s/.*/export GIT_'$uid'_NAME='\''&'\''/p
54
55                         g
56                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
57                         s/'\''/'\''\'\'\''/g
58                         s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
59
60                         g
61                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
62                         s/'\''/'\''\'\'\''/g
63                         s/.*/export GIT_'$uid'_DATE='\''&'\''/p
64
65                         q
66                 }
67         '
68
69         LANG=C LC_ALL=C sed -ne "$pick_id_script"
70         # Ensure non-empty id name.
71         echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
72 }
73
74 tempdir=.git-rewrite
75 filter_env=
76 filter_tree=
77 filter_index=
78 filter_parent=
79 filter_msg=cat
80 filter_commit='git commit-tree "$@"'
81 filter_tag_name=
82 filter_subdir=
83 while case "$#" in 0) usage;; esac
84 do
85         case "$1" in
86         --)
87                 shift
88                 break
89                 ;;
90         -*)
91                 ;;
92         *)
93                 break;
94         esac
95
96         # all switches take one argument
97         ARG="$1"
98         case "$#" in 1) usage ;; esac
99         shift
100         OPTARG="$1"
101         shift
102
103         case "$ARG" in
104         -d)
105                 tempdir="$OPTARG"
106                 ;;
107         --env-filter)
108                 filter_env="$OPTARG"
109                 ;;
110         --tree-filter)
111                 filter_tree="$OPTARG"
112                 ;;
113         --index-filter)
114                 filter_index="$OPTARG"
115                 ;;
116         --parent-filter)
117                 filter_parent="$OPTARG"
118                 ;;
119         --msg-filter)
120                 filter_msg="$OPTARG"
121                 ;;
122         --commit-filter)
123                 filter_commit="$OPTARG"
124                 ;;
125         --tag-name-filter)
126                 filter_tag_name="$OPTARG"
127                 ;;
128         --subdirectory-filter)
129                 filter_subdir="$OPTARG"
130                 ;;
131         *)
132                 usage
133                 ;;
134         esac
135 done
136
137 dstbranch="$1"
138 shift
139 test -n "$dstbranch" || die "missing branch name"
140 git show-ref "refs/heads/$dstbranch" 2> /dev/null &&
141         die "branch $dstbranch already exists"
142
143 test ! -e "$tempdir" || die "$tempdir already exists, please remove it"
144 mkdir -p "$tempdir/t"
145 cd "$tempdir/t"
146 workdir="$(pwd)"
147
148 case "$GIT_DIR" in
149 /*)
150         ;;
151 *)
152         GIT_DIR="$(pwd)/../../$GIT_DIR"
153         ;;
154 esac
155 export GIT_DIR GIT_WORK_TREE=.
156
157 export GIT_INDEX_FILE="$(pwd)/../index"
158 git read-tree # seed the index file
159
160 ret=0
161
162
163 mkdir ../map # map old->new commit ids for rewriting parents
164
165 case "$filter_subdir" in
166 "")
167         git rev-list --reverse --topo-order --default HEAD \
168                 --parents "$@"
169         ;;
170 *)
171         git rev-list --reverse --topo-order --default HEAD \
172                 --parents --full-history "$@" -- "$filter_subdir"
173 esac > ../revs
174 commits=$(wc -l <../revs | tr -d " ")
175
176 test $commits -eq 0 && die "Found nothing to rewrite"
177
178 i=0
179 while read commit parents; do
180         i=$(($i+1))
181         printf "\rRewrite $commit ($i/$commits)"
182
183         case "$filter_subdir" in
184         "")
185                 git read-tree -i -m $commit
186                 ;;
187         *)
188                 git read-tree -i -m $commit:"$filter_subdir"
189         esac
190
191         export GIT_COMMIT=$commit
192         git cat-file commit "$commit" >../commit
193
194         eval "$(set_ident AUTHOR <../commit)" ||
195                 die "setting author failed for commit $commit"
196         eval "$(set_ident COMMITTER <../commit)" ||
197                 die "setting committer failed for commit $commit"
198         eval "$filter_env" < /dev/null ||
199                 die "env filter failed: $filter_env"
200
201         if [ "$filter_tree" ]; then
202                 git checkout-index -f -u -a
203                 # files that $commit removed are now still in the working tree;
204                 # remove them, else they would be added again
205                 git ls-files -z --others | xargs -0 rm -f
206                 eval "$filter_tree" < /dev/null ||
207                         die "tree filter failed: $filter_tree"
208
209                 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
210                         xargs -0 git update-index --add --replace --remove
211                 git ls-files -z --others | \
212                         xargs -0 git update-index --add --replace --remove
213         fi
214
215         eval "$filter_index" < /dev/null ||
216                 die "index filter failed: $filter_index"
217
218         parentstr=
219         for parent in $parents; do
220                 for reparent in $(map "$parent"); do
221                         parentstr="$parentstr -p $reparent"
222                 done
223         done
224         if [ "$filter_parent" ]; then
225                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
226                                 die "parent filter failed: $filter_parent"
227         fi
228
229         sed -e '1,/^$/d' <../commit | \
230                 eval "$filter_msg" > ../message ||
231                         die "msg filter failed: $filter_msg"
232         sh -c "$filter_commit" "git commit-tree" \
233                 $(git write-tree) $parentstr < ../message > ../map/$commit
234 done <../revs
235
236 src_head=$(tail -n 1 ../revs | sed -e 's/ .*//')
237 target_head=$(head -n 1 ../map/$src_head)
238 case "$target_head" in
239 '')
240         echo Nothing rewritten
241         ;;
242 *)
243         git update-ref refs/heads/"$dstbranch" $target_head
244         if [ $(wc -l <../map/$src_head) -gt 1 ]; then
245                 echo "WARNING: Your commit filter caused the head commit to expand to several rewritten commits. Only the first such commit was recorded as the current $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
246                 sed 's/^/       /' ../map/$src_head >&2
247                 ret=1
248         fi
249         ;;
250 esac
251
252 if [ "$filter_tag_name" ]; then
253         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
254         while read sha1 type ref; do
255                 ref="${ref#refs/tags/}"
256                 # XXX: Rewrite tagged trees as well?
257                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
258                         continue;
259                 fi
260
261                 if [ "$type" = "tag" ]; then
262                         # Dereference to a commit
263                         sha1t="$sha1"
264                         sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
265                 fi
266
267                 [ -f "../map/$sha1" ] || continue
268                 new_sha1="$(cat "../map/$sha1")"
269                 export GIT_COMMIT="$sha1"
270                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
271                         die "tag name filter failed: $filter_tag_name"
272
273                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
274
275                 if [ "$type" = "tag" ]; then
276                         # Warn that we are not rewriting the tag object itself.
277                         warn "unreferencing tag object $sha1t"
278                 fi
279
280                 git update-ref "refs/tags/$new_ref" "$new_sha1"
281         done
282 fi
283
284 cd ../..
285 rm -rf "$tempdir"
286 printf "\nRewritten history saved to the $dstbranch branch\n"
287
288 exit $ret