Fix typo in draft 1.5.4 release notes
[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 warn () {
12         echo "$*" >&2
13 }
14
15 map()
16 {
17         # if it was not rewritten, take the original
18         if test -r "$workdir/../map/$1"
19         then
20                 cat "$workdir/../map/$1"
21         else
22                 echo "$1"
23         fi
24 }
25
26 # if you run 'skip_commit "$@"' in a commit filter, it will print
27 # the (mapped) parents, effectively skipping the commit.
28
29 skip_commit()
30 {
31         shift;
32         while [ -n "$1" ];
33         do
34                 shift;
35                 map "$1";
36                 shift;
37         done;
38 }
39
40 # override die(): this version puts in an extra line break, so that
41 # the progress is still visible
42
43 die()
44 {
45         echo >&2
46         echo "$*" >&2
47         exit 1
48 }
49
50 # When piped a commit, output a script to set the ident of either
51 # "author" or "committer
52
53 set_ident () {
54         lid="$(echo "$1" | tr "A-Z" "a-z")"
55         uid="$(echo "$1" | tr "a-z" "A-Z")"
56         pick_id_script='
57                 /^'$lid' /{
58                         s/'\''/'\''\\'\'\''/g
59                         h
60                         s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
61                         s/'\''/'\''\'\'\''/g
62                         s/.*/export GIT_'$uid'_NAME='\''&'\''/p
63
64                         g
65                         s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
66                         s/'\''/'\''\'\'\''/g
67                         s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
68
69                         g
70                         s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
71                         s/'\''/'\''\'\'\''/g
72                         s/.*/export GIT_'$uid'_DATE='\''&'\''/p
73
74                         q
75                 }
76         '
77
78         LANG=C LC_ALL=C sed -ne "$pick_id_script"
79         # Ensure non-empty id name.
80         echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
81 }
82
83 # This script can be sourced by the commit filter to get the functions
84 test "a$SOURCE_FUNCTIONS" = a1 && return
85 this_script="$(cd "$(dirname "$0")"; pwd)"/$(basename "$0")
86 export this_script
87
88 USAGE="[--env-filter <command>] [--tree-filter <command>] \
89 [--index-filter <command>] [--parent-filter <command>] \
90 [--msg-filter <command>] [--commit-filter <command>] \
91 [--tag-name-filter <command>] [--subdirectory-filter <directory>] \
92 [--original <namespace>] [-d <directory>] [-f | --force] \
93 [<rev-list options>...]"
94
95 OPTIONS_SPEC=
96 . git-sh-setup
97
98 git diff-files --quiet &&
99         git diff-index --cached --quiet HEAD ||
100         die "Cannot rewrite branch(es) with a dirty working directory."
101
102 tempdir=.git-rewrite
103 filter_env=
104 filter_tree=
105 filter_index=
106 filter_parent=
107 filter_msg=cat
108 filter_commit='git commit-tree "$@"'
109 filter_tag_name=
110 filter_subdir=
111 orig_namespace=refs/original/
112 force=
113 while :
114 do
115         test $# = 0 && usage
116         case "$1" in
117         --)
118                 shift
119                 break
120                 ;;
121         --force|-f)
122                 shift
123                 force=t
124                 continue
125                 ;;
126         -*)
127                 ;;
128         *)
129                 break;
130         esac
131
132         # all switches take one argument
133         ARG="$1"
134         case "$#" in 1) usage ;; esac
135         shift
136         OPTARG="$1"
137         shift
138
139         case "$ARG" in
140         -d)
141                 tempdir="$OPTARG"
142                 ;;
143         --env-filter)
144                 filter_env="$OPTARG"
145                 ;;
146         --tree-filter)
147                 filter_tree="$OPTARG"
148                 ;;
149         --index-filter)
150                 filter_index="$OPTARG"
151                 ;;
152         --parent-filter)
153                 filter_parent="$OPTARG"
154                 ;;
155         --msg-filter)
156                 filter_msg="$OPTARG"
157                 ;;
158         --commit-filter)
159                 filter_commit='SOURCE_FUNCTIONS=1 . "$this_script";'" $OPTARG"
160                 ;;
161         --tag-name-filter)
162                 filter_tag_name="$OPTARG"
163                 ;;
164         --subdirectory-filter)
165                 filter_subdir="$OPTARG"
166                 ;;
167         --original)
168                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
169                 ;;
170         *)
171                 usage
172                 ;;
173         esac
174 done
175
176 case "$force" in
177 t)
178         rm -rf "$tempdir"
179 ;;
180 '')
181         test -d "$tempdir" &&
182                 die "$tempdir already exists, please remove it"
183 esac
184 mkdir -p "$tempdir/t" &&
185 tempdir="$(cd "$tempdir"; pwd)" &&
186 cd "$tempdir/t" &&
187 workdir="$(pwd)" ||
188 die ""
189
190 # Make sure refs/original is empty
191 git for-each-ref > "$tempdir"/backup-refs
192 while read sha1 type name
193 do
194         case "$force,$name" in
195         ,$orig_namespace*)
196                 die "Namespace $orig_namespace not empty"
197         ;;
198         t,$orig_namespace*)
199                 git update-ref -d "$name" $sha1
200         ;;
201         esac
202 done < "$tempdir"/backup-refs
203
204 ORIG_GIT_DIR="$GIT_DIR"
205 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
206 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
207 export GIT_DIR GIT_WORK_TREE=.
208
209 # These refs should be updated if their heads were rewritten
210
211 git rev-parse --revs-only --symbolic "$@" |
212 while read ref
213 do
214         # normalize ref
215         case "$ref" in
216         HEAD)
217                 ref="$(git symbolic-ref "$ref")"
218         ;;
219         refs/*)
220         ;;
221         *)
222                 ref="$(git for-each-ref --format='%(refname)' |
223                         grep /"$ref")"
224         esac
225
226         git check-ref-format "$ref" && echo "$ref"
227 done > "$tempdir"/heads
228
229 test -s "$tempdir"/heads ||
230         die "Which ref do you want to rewrite?"
231
232 export GIT_INDEX_FILE="$(pwd)/../index"
233 git read-tree || die "Could not seed the index"
234
235 ret=0
236
237 # map old->new commit ids for rewriting parents
238 mkdir ../map || die "Could not create map/ directory"
239
240 case "$filter_subdir" in
241 "")
242         git rev-list --reverse --topo-order --default HEAD \
243                 --parents "$@"
244         ;;
245 *)
246         git rev-list --reverse --topo-order --default HEAD \
247                 --parents --full-history "$@" -- "$filter_subdir"
248 esac > ../revs || die "Could not get the commits"
249 commits=$(wc -l <../revs | tr -d " ")
250
251 test $commits -eq 0 && die "Found nothing to rewrite"
252
253 # Rewrite the commits
254
255 i=0
256 while read commit parents; do
257         i=$(($i+1))
258         printf "\rRewrite $commit ($i/$commits)"
259
260         case "$filter_subdir" in
261         "")
262                 git read-tree -i -m $commit
263                 ;;
264         *)
265                 git read-tree -i -m $commit:"$filter_subdir"
266         esac || die "Could not initialize the index"
267
268         export GIT_COMMIT=$commit
269         git cat-file commit "$commit" >../commit ||
270                 die "Cannot read commit $commit"
271
272         eval "$(set_ident AUTHOR <../commit)" ||
273                 die "setting author failed for commit $commit"
274         eval "$(set_ident COMMITTER <../commit)" ||
275                 die "setting committer failed for commit $commit"
276         eval "$filter_env" < /dev/null ||
277                 die "env filter failed: $filter_env"
278
279         if [ "$filter_tree" ]; then
280                 git checkout-index -f -u -a ||
281                         die "Could not checkout the index"
282                 # files that $commit removed are now still in the working tree;
283                 # remove them, else they would be added again
284                 git ls-files -z --others | xargs -0 rm -f
285                 eval "$filter_tree" < /dev/null ||
286                         die "tree filter failed: $filter_tree"
287
288                 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
289                         xargs -0 git update-index --add --replace --remove
290                 git ls-files -z --others | \
291                         xargs -0 git update-index --add --replace --remove
292         fi
293
294         eval "$filter_index" < /dev/null ||
295                 die "index filter failed: $filter_index"
296
297         parentstr=
298         for parent in $parents; do
299                 for reparent in $(map "$parent"); do
300                         parentstr="$parentstr -p $reparent"
301                 done
302         done
303         if [ "$filter_parent" ]; then
304                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
305                                 die "parent filter failed: $filter_parent"
306         fi
307
308         sed -e '1,/^$/d' <../commit | \
309                 eval "$filter_msg" > ../message ||
310                         die "msg filter failed: $filter_msg"
311         sh -c "$filter_commit" "git commit-tree" \
312                 $(git write-tree) $parentstr < ../message > ../map/$commit
313 done <../revs
314
315 # In case of a subdirectory filter, it is possible that a specified head
316 # is not in the set of rewritten commits, because it was pruned by the
317 # revision walker.  Fix it by mapping these heads to the next rewritten
318 # ancestor(s), i.e. the boundaries in the set of rewritten commits.
319
320 # NEEDSWORK: we should sort the unmapped refs topologically first
321 while read ref
322 do
323         sha1=$(git rev-parse "$ref"^0)
324         test -f "$workdir"/../map/$sha1 && continue
325         # Assign the boundarie(s) in the set of rewritten commits
326         # as the replacement commit(s).
327         # (This would look a bit nicer if --not --stdin worked.)
328         for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
329                 git rev-list $ref --boundary --stdin |
330                 sed -n "s/^-//p")
331         do
332                 map $p >> "$workdir"/../map/$sha1
333         done
334 done < "$tempdir"/heads
335
336 # Finally update the refs
337
338 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
339 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
340 count=0
341 echo
342 while read ref
343 do
344         # avoid rewriting a ref twice
345         test -f "$orig_namespace$ref" && continue
346
347         sha1=$(git rev-parse "$ref"^0)
348         rewritten=$(map $sha1)
349
350         test $sha1 = "$rewritten" &&
351                 warn "WARNING: Ref '$ref' is unchanged" &&
352                 continue
353
354         case "$rewritten" in
355         '')
356                 echo "Ref '$ref' was deleted"
357                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
358                         die "Could not delete $ref"
359         ;;
360         $_x40)
361                 echo "Ref '$ref' was rewritten"
362                 git update-ref -m "filter-branch: rewrite" \
363                                 "$ref" $rewritten $sha1 ||
364                         die "Could not rewrite $ref"
365         ;;
366         *)
367                 # NEEDSWORK: possibly add -Werror, making this an error
368                 warn "WARNING: '$ref' was rewritten into multiple commits:"
369                 warn "$rewritten"
370                 warn "WARNING: Ref '$ref' points to the first one now."
371                 rewritten=$(echo "$rewritten" | head -n 1)
372                 git update-ref -m "filter-branch: rewrite to first" \
373                                 "$ref" $rewritten $sha1 ||
374                         die "Could not rewrite $ref"
375         ;;
376         esac
377         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
378         count=$(($count+1))
379 done < "$tempdir"/heads
380
381 # TODO: This should possibly go, with the semantics that all positive given
382 #       refs are updated, and their original heads stored in refs/original/
383 # Filter tags
384
385 if [ "$filter_tag_name" ]; then
386         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
387         while read sha1 type ref; do
388                 ref="${ref#refs/tags/}"
389                 # XXX: Rewrite tagged trees as well?
390                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
391                         continue;
392                 fi
393
394                 if [ "$type" = "tag" ]; then
395                         # Dereference to a commit
396                         sha1t="$sha1"
397                         sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
398                 fi
399
400                 [ -f "../map/$sha1" ] || continue
401                 new_sha1="$(cat "../map/$sha1")"
402                 export GIT_COMMIT="$sha1"
403                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
404                         die "tag name filter failed: $filter_tag_name"
405
406                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
407
408                 if [ "$type" = "tag" ]; then
409                         # Warn that we are not rewriting the tag object itself.
410                         warn "unreferencing tag object $sha1t"
411                 fi
412
413                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
414                         die "Could not write tag $new_ref"
415         done
416 fi
417
418 cd ../..
419 rm -rf "$tempdir"
420 echo
421 test $count -gt 0 && echo "These refs were rewritten:"
422 git show-ref | grep ^"$orig_namespace"
423
424 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
425 test -z "$ORIG_GIT_DIR" || GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
426 test -z "$ORIG_GIT_WORK_TREE" || GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
427         export GIT_WORK_TREE
428 test -z "$ORIG_GIT_INDEX_FILE" || GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
429         export GIT_INDEX_FILE
430 git read-tree -u -m HEAD
431
432 exit $ret