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# The following functions will also be available in the commit filter:
12
13functions=$(cat << \EOF
14warn () {
15 echo "$*" >&2
16}
17
18map()
19{
20 # if it was not rewritten, take the original
21 if test -r "$workdir/../map/$1"
22 then
23 cat "$workdir/../map/$1"
24 else
25 echo "$1"
26 fi
27}
28
29# if you run 'skip_commit "$@"' in a commit filter, it will print
30# the (mapped) parents, effectively skipping the commit.
31
32skip_commit()
33{
34 shift;
35 while [ -n "$1" ];
36 do
37 shift;
38 map "$1";
39 shift;
40 done;
41}
42
43# override die(): this version puts in an extra line break, so that
44# the progress is still visible
45
46die()
47{
48 echo >&2
49 echo "$*" >&2
50 exit 1
51}
52EOF
53)
54
55eval "$functions"
56
57# When piped a commit, output a script to set the ident of either
58# "author" or "committer
59
60set_ident () {
61 lid="$(echo "$1" | tr "[A-Z]" "[a-z]")"
62 uid="$(echo "$1" | tr "[a-z]" "[A-Z]")"
63 pick_id_script='
64 /^'$lid' /{
65 s/'\''/'\''\\'\'\''/g
66 h
67 s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
68 s/'\''/'\''\'\'\''/g
69 s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
70
71 g
72 s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
73 s/'\''/'\''\'\'\''/g
74 s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
75
76 g
77 s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
78 s/'\''/'\''\'\'\''/g
79 s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
80
81 q
82 }
83 '
84
85 LANG=C LC_ALL=C sed -ne "$pick_id_script"
86 # Ensure non-empty id name.
87 echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
88}
89
90USAGE="[--env-filter <command>] [--tree-filter <command>] \
91[--index-filter <command>] [--parent-filter <command>] \
92[--msg-filter <command>] [--commit-filter <command>] \
93[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
94[--original <namespace>] [-d <directory>] [-f | --force] \
95[<rev-list options>...]"
96
97OPTIONS_SPEC=
98. git-sh-setup
99
100if [ "$(is_bare_repository)" = false ]; then
101 git diff-files --quiet &&
102 git diff-index --cached --quiet HEAD -- ||
103 die "Cannot rewrite branch(es) with a dirty working directory."
104fi
105
106tempdir=.git-rewrite
107filter_env=
108filter_tree=
109filter_index=
110filter_parent=
111filter_msg=cat
112filter_commit='git commit-tree "$@"'
113filter_tag_name=
114filter_subdir=
115orig_namespace=refs/original/
116force=
117while :
118do
119 case "$1" in
120 --)
121 shift
122 break
123 ;;
124 --force|-f)
125 shift
126 force=t
127 continue
128 ;;
129 -*)
130 ;;
131 *)
132 break;
133 esac
134
135 # all switches take one argument
136 ARG="$1"
137 case "$#" in 1) usage ;; esac
138 shift
139 OPTARG="$1"
140 shift
141
142 case "$ARG" in
143 -d)
144 tempdir="$OPTARG"
145 ;;
146 --env-filter)
147 filter_env="$OPTARG"
148 ;;
149 --tree-filter)
150 filter_tree="$OPTARG"
151 ;;
152 --index-filter)
153 filter_index="$OPTARG"
154 ;;
155 --parent-filter)
156 filter_parent="$OPTARG"
157 ;;
158 --msg-filter)
159 filter_msg="$OPTARG"
160 ;;
161 --commit-filter)
162 filter_commit="$functions; $OPTARG"
163 ;;
164 --tag-name-filter)
165 filter_tag_name="$OPTARG"
166 ;;
167 --subdirectory-filter)
168 filter_subdir="$OPTARG"
169 ;;
170 --original)
171 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
172 ;;
173 *)
174 usage
175 ;;
176 esac
177done
178
179case "$force" in
180t)
181 rm -rf "$tempdir"
182;;
183'')
184 test -d "$tempdir" &&
185 die "$tempdir already exists, please remove it"
186esac
187mkdir -p "$tempdir/t" &&
188tempdir="$(cd "$tempdir"; pwd)" &&
189cd "$tempdir/t" &&
190workdir="$(pwd)" ||
191die ""
192
193# Remove tempdir on exit
194trap 'cd ../..; rm -rf "$tempdir"' 0
195
196# Make sure refs/original is empty
197git for-each-ref > "$tempdir"/backup-refs
198while read sha1 type name
199do
200 case "$force,$name" in
201 ,$orig_namespace*)
202 die "Namespace $orig_namespace not empty"
203 ;;
204 t,$orig_namespace*)
205 git update-ref -d "$name" $sha1
206 ;;
207 esac
208done < "$tempdir"/backup-refs
209
210ORIG_GIT_DIR="$GIT_DIR"
211ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
212ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
213GIT_WORK_TREE=.
214export GIT_DIR GIT_WORK_TREE
215
216# The refs should be updated if their heads were rewritten
217git rev-parse --no-flags --revs-only --symbolic-full-name --default HEAD "$@" |
218sed -e '/^^/d' >"$tempdir"/heads
219
220test -s "$tempdir"/heads ||
221 die "Which ref do you want to rewrite?"
222
223GIT_INDEX_FILE="$(pwd)/../index"
224export GIT_INDEX_FILE
225git read-tree || die "Could not seed the index"
226
227ret=0
228
229# map old->new commit ids for rewriting parents
230mkdir ../map || die "Could not create map/ directory"
231
232case "$filter_subdir" in
233"")
234 git rev-list --reverse --topo-order --default HEAD \
235 --parents "$@"
236 ;;
237*)
238 git rev-list --reverse --topo-order --default HEAD \
239 --parents "$@" -- "$filter_subdir"
240esac > ../revs || die "Could not get the commits"
241commits=$(wc -l <../revs | tr -d " ")
242
243test $commits -eq 0 && die "Found nothing to rewrite"
244
245# Rewrite the commits
246
247i=0
248while read commit parents; do
249 i=$(($i+1))
250 printf "\rRewrite $commit ($i/$commits)"
251
252 case "$filter_subdir" in
253 "")
254 git read-tree -i -m $commit
255 ;;
256 *)
257 # The commit may not have the subdirectory at all
258 err=$(git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
259 if ! git rev-parse --verify $commit:"$filter_subdir" 2>/dev/null
260 then
261 rm -f "$GIT_INDEX_FILE"
262 else
263 echo >&2 "$err"
264 false
265 fi
266 }
267 esac || die "Could not initialize the index"
268
269 GIT_COMMIT=$commit
270 export GIT_COMMIT
271 git cat-file commit "$commit" >../commit ||
272 die "Cannot read commit $commit"
273
274 eval "$(set_ident AUTHOR <../commit)" ||
275 die "setting author failed for commit $commit"
276 eval "$(set_ident COMMITTER <../commit)" ||
277 die "setting committer failed for commit $commit"
278 eval "$filter_env" < /dev/null ||
279 die "env filter failed: $filter_env"
280
281 if [ "$filter_tree" ]; then
282 git checkout-index -f -u -a ||
283 die "Could not checkout the index"
284 # files that $commit removed are now still in the working tree;
285 # remove them, else they would be added again
286 git clean -d -q -f -x
287 eval "$filter_tree" < /dev/null ||
288 die "tree filter failed: $filter_tree"
289
290 (
291 git diff-index -r --name-only $commit
292 git ls-files --others
293 ) |
294 git update-index --add --replace --remove --stdin
295 fi
296
297 eval "$filter_index" < /dev/null ||
298 die "index filter failed: $filter_index"
299
300 parentstr=
301 for parent in $parents; do
302 for reparent in $(map "$parent"); do
303 parentstr="$parentstr -p $reparent"
304 done
305 done
306 if [ "$filter_parent" ]; then
307 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
308 die "parent filter failed: $filter_parent"
309 fi
310
311 sed -e '1,/^$/d' <../commit | \
312 eval "$filter_msg" > ../message ||
313 die "msg filter failed: $filter_msg"
314 @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
315 $(git write-tree) $parentstr < ../message > ../map/$commit
316done <../revs
317
318# In case of a subdirectory filter, it is possible that a specified head
319# is not in the set of rewritten commits, because it was pruned by the
320# revision walker. Fix it by mapping these heads to the next rewritten
321# ancestor(s), i.e. the boundaries in the set of rewritten commits.
322
323# NEEDSWORK: we should sort the unmapped refs topologically first
324while read ref
325do
326 sha1=$(git rev-parse "$ref"^0)
327 test -f "$workdir"/../map/$sha1 && continue
328 # Assign the boundarie(s) in the set of rewritten commits
329 # as the replacement commit(s).
330 # (This would look a bit nicer if --not --stdin worked.)
331 for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
332 git rev-list $ref --boundary --stdin |
333 sed -n "s/^-//p")
334 do
335 map $p >> "$workdir"/../map/$sha1
336 done
337done < "$tempdir"/heads
338
339# Finally update the refs
340
341_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
342_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
343echo
344while read ref
345do
346 # avoid rewriting a ref twice
347 test -f "$orig_namespace$ref" && continue
348
349 sha1=$(git rev-parse "$ref"^0)
350 rewritten=$(map $sha1)
351
352 test $sha1 = "$rewritten" &&
353 warn "WARNING: Ref '$ref' is unchanged" &&
354 continue
355
356 case "$rewritten" in
357 '')
358 echo "Ref '$ref' was deleted"
359 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
360 die "Could not delete $ref"
361 ;;
362 $_x40)
363 echo "Ref '$ref' was rewritten"
364 if ! git update-ref -m "filter-branch: rewrite" \
365 "$ref" $rewritten $sha1 2>/dev/null; then
366 if test $(git cat-file -t "$ref") = tag; then
367 if test -z "$filter_tag_name"; then
368 warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
369 warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
370 fi
371 else
372 die "Could not rewrite $ref"
373 fi
374 fi
375 ;;
376 *)
377 # NEEDSWORK: possibly add -Werror, making this an error
378 warn "WARNING: '$ref' was rewritten into multiple commits:"
379 warn "$rewritten"
380 warn "WARNING: Ref '$ref' points to the first one now."
381 rewritten=$(echo "$rewritten" | head -n 1)
382 git update-ref -m "filter-branch: rewrite to first" \
383 "$ref" $rewritten $sha1 ||
384 die "Could not rewrite $ref"
385 ;;
386 esac
387 git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
388done < "$tempdir"/heads
389
390# TODO: This should possibly go, with the semantics that all positive given
391# refs are updated, and their original heads stored in refs/original/
392# Filter tags
393
394if [ "$filter_tag_name" ]; then
395 git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
396 while read sha1 type ref; do
397 ref="${ref#refs/tags/}"
398 # XXX: Rewrite tagged trees as well?
399 if [ "$type" != "commit" -a "$type" != "tag" ]; then
400 continue;
401 fi
402
403 if [ "$type" = "tag" ]; then
404 # Dereference to a commit
405 sha1t="$sha1"
406 sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
407 fi
408
409 [ -f "../map/$sha1" ] || continue
410 new_sha1="$(cat "../map/$sha1")"
411 GIT_COMMIT="$sha1"
412 export GIT_COMMIT
413 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
414 die "tag name filter failed: $filter_tag_name"
415
416 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
417
418 if [ "$type" = "tag" ]; then
419 new_sha1=$(git cat-file tag "$ref" |
420 sed -n \
421 -e "1,/^$/{
422 s/^object .*/object $new_sha1/
423 s/^type .*/type commit/
424 s/^tag .*/tag $new_ref/
425 }" \
426 -e '/^-----BEGIN PGP SIGNATURE-----/q' \
427 -e 'p' |
428 git mktag) ||
429 die "Could not create new tag object for $ref"
430 if git cat-file tag "$ref" | \
431 grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
432 then
433 warn "gpg signature stripped from tag object $sha1t"
434 fi
435 fi
436
437 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
438 die "Could not write tag $new_ref"
439 done
440fi
441
442cd ../..
443rm -rf "$tempdir"
444
445trap - 0
446
447if [ "$(is_bare_repository)" = false ]; then
448 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
449 test -z "$ORIG_GIT_DIR" || {
450 GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
451 }
452 test -z "$ORIG_GIT_WORK_TREE" || {
453 GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
454 export GIT_WORK_TREE
455 }
456 test -z "$ORIG_GIT_INDEX_FILE" || {
457 GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
458 export GIT_INDEX_FILE
459 }
460 git read-tree -u -m HEAD
461fi
462
463exit $ret