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 "$1";
39 shift;
40 done;
41}
42
43# if you run 'git_commit_non_empty_tree "$@"' in a commit filter,
44# it will skip commits that leave the tree untouched, commit the other.
45git_commit_non_empty_tree()
46{
47 if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
48 map "$3"
49 else
50 git commit-tree "$@"
51 fi
52}
53# override die(): this version puts in an extra line break, so that
54# the progress is still visible
55
56die()
57{
58 echo >&2
59 echo "$*" >&2
60 exit 1
61}
62EOF
63)
64
65eval "$functions"
66
67# When piped a commit, output a script to set the ident of either
68# "author" or "committer
69
70set_ident () {
71 lid="$(echo "$1" | tr "[A-Z]" "[a-z]")"
72 uid="$(echo "$1" | tr "[a-z]" "[A-Z]")"
73 pick_id_script='
74 /^'$lid' /{
75 s/'\''/'\''\\'\'\''/g
76 h
77 s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
78 s/'\''/'\''\'\'\''/g
79 s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
80
81 g
82 s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
83 s/'\''/'\''\'\'\''/g
84 s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
85
86 g
87 s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
88 s/'\''/'\''\'\'\''/g
89 s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
90
91 q
92 }
93 '
94
95 LANG=C LC_ALL=C sed -ne "$pick_id_script"
96 # Ensure non-empty id name.
97 echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
98}
99
100USAGE="[--env-filter <command>] [--tree-filter <command>]
101 [--index-filter <command>] [--parent-filter <command>]
102 [--msg-filter <command>] [--commit-filter <command>]
103 [--tag-name-filter <command>] [--subdirectory-filter <directory>]
104 [--original <namespace>] [-d <directory>] [-f | --force]
105 [<rev-list options>...]"
106
107OPTIONS_SPEC=
108. git-sh-setup
109
110if [ "$(is_bare_repository)" = false ]; then
111 git diff-files --ignore-submodules --quiet &&
112 git diff-index --cached --quiet HEAD -- ||
113 die "Cannot rewrite branch(es) with a dirty working directory."
114fi
115
116tempdir=.git-rewrite
117filter_env=
118filter_tree=
119filter_index=
120filter_parent=
121filter_msg=cat
122filter_commit=
123filter_tag_name=
124filter_subdir=
125orig_namespace=refs/original/
126force=
127prune_empty=
128while :
129do
130 case "$1" in
131 --)
132 shift
133 break
134 ;;
135 --force|-f)
136 shift
137 force=t
138 continue
139 ;;
140 --prune-empty)
141 shift
142 prune_empty=t
143 continue
144 ;;
145 -*)
146 ;;
147 *)
148 break;
149 esac
150
151 # all switches take one argument
152 ARG="$1"
153 case "$#" in 1) usage ;; esac
154 shift
155 OPTARG="$1"
156 shift
157
158 case "$ARG" in
159 -d)
160 tempdir="$OPTARG"
161 ;;
162 --env-filter)
163 filter_env="$OPTARG"
164 ;;
165 --tree-filter)
166 filter_tree="$OPTARG"
167 ;;
168 --index-filter)
169 filter_index="$OPTARG"
170 ;;
171 --parent-filter)
172 filter_parent="$OPTARG"
173 ;;
174 --msg-filter)
175 filter_msg="$OPTARG"
176 ;;
177 --commit-filter)
178 filter_commit="$functions; $OPTARG"
179 ;;
180 --tag-name-filter)
181 filter_tag_name="$OPTARG"
182 ;;
183 --subdirectory-filter)
184 filter_subdir="$OPTARG"
185 ;;
186 --original)
187 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
188 ;;
189 *)
190 usage
191 ;;
192 esac
193done
194
195case "$prune_empty,$filter_commit" in
196,)
197 filter_commit='git commit-tree "$@"';;
198t,)
199 filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
200,*)
201 ;;
202*)
203 die "Cannot set --prune-empty and --filter-commit at the same time"
204esac
205
206case "$force" in
207t)
208 rm -rf "$tempdir"
209;;
210'')
211 test -d "$tempdir" &&
212 die "$tempdir already exists, please remove it"
213esac
214mkdir -p "$tempdir/t" &&
215tempdir="$(cd "$tempdir"; pwd)" &&
216cd "$tempdir/t" &&
217workdir="$(pwd)" ||
218die ""
219
220# Remove tempdir on exit
221trap 'cd ../..; rm -rf "$tempdir"' 0
222
223ORIG_GIT_DIR="$GIT_DIR"
224ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
225ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
226GIT_WORK_TREE=.
227export GIT_DIR GIT_WORK_TREE
228
229# Make sure refs/original is empty
230git for-each-ref > "$tempdir"/backup-refs || exit
231while read sha1 type name
232do
233 case "$force,$name" in
234 ,$orig_namespace*)
235 die "Cannot create a new backup.
236A previous backup already exists in $orig_namespace
237Force overwriting the backup with -f"
238 ;;
239 t,$orig_namespace*)
240 git update-ref -d "$name" $sha1
241 ;;
242 esac
243done < "$tempdir"/backup-refs
244
245# The refs should be updated if their heads were rewritten
246git rev-parse --no-flags --revs-only --symbolic-full-name \
247 --default HEAD "$@" > "$tempdir"/raw-heads || exit
248sed -e '/^^/d' "$tempdir"/raw-heads >"$tempdir"/heads
249
250test -s "$tempdir"/heads ||
251 die "Which ref do you want to rewrite?"
252
253GIT_INDEX_FILE="$(pwd)/../index"
254export GIT_INDEX_FILE
255
256# map old->new commit ids for rewriting parents
257mkdir ../map || die "Could not create map/ directory"
258
259case "$filter_subdir" in
260"")
261 git rev-list --reverse --topo-order --default HEAD \
262 --parents --simplify-merges "$@"
263 ;;
264*)
265 git rev-list --reverse --topo-order --default HEAD \
266 --parents --simplify-merges "$@" -- "$filter_subdir"
267esac > ../revs || die "Could not get the commits"
268commits=$(wc -l <../revs | tr -d " ")
269
270test $commits -eq 0 && die "Found nothing to rewrite"
271
272# Rewrite the commits
273
274git_filter_branch__commit_count=0
275while read commit parents; do
276 git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
277 printf "\rRewrite $commit ($git_filter_branch__commit_count/$commits)"
278
279 case "$filter_subdir" in
280 "")
281 git read-tree -i -m $commit
282 ;;
283 *)
284 # The commit may not have the subdirectory at all
285 err=$(git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
286 if ! git rev-parse -q --verify $commit:"$filter_subdir"
287 then
288 rm -f "$GIT_INDEX_FILE"
289 else
290 echo >&2 "$err"
291 false
292 fi
293 }
294 esac || die "Could not initialize the index"
295
296 GIT_COMMIT=$commit
297 export GIT_COMMIT
298 git cat-file commit "$commit" >../commit ||
299 die "Cannot read commit $commit"
300
301 eval "$(set_ident AUTHOR <../commit)" ||
302 die "setting author failed for commit $commit"
303 eval "$(set_ident COMMITTER <../commit)" ||
304 die "setting committer failed for commit $commit"
305 eval "$filter_env" < /dev/null ||
306 die "env filter failed: $filter_env"
307
308 if [ "$filter_tree" ]; then
309 git checkout-index -f -u -a ||
310 die "Could not checkout the index"
311 # files that $commit removed are now still in the working tree;
312 # remove them, else they would be added again
313 git clean -d -q -f -x
314 eval "$filter_tree" < /dev/null ||
315 die "tree filter failed: $filter_tree"
316
317 (
318 git diff-index -r --name-only $commit &&
319 git ls-files --others
320 ) > "$tempdir"/tree-state || exit
321 git update-index --add --replace --remove --stdin \
322 < "$tempdir"/tree-state || exit
323 fi
324
325 eval "$filter_index" < /dev/null ||
326 die "index filter failed: $filter_index"
327
328 parentstr=
329 for parent in $parents; do
330 for reparent in $(map "$parent"); do
331 parentstr="$parentstr -p $reparent"
332 done
333 done
334 if [ "$filter_parent" ]; then
335 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
336 die "parent filter failed: $filter_parent"
337 fi
338
339 sed -e '1,/^$/d' <../commit | \
340 eval "$filter_msg" > ../message ||
341 die "msg filter failed: $filter_msg"
342 @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
343 $(git write-tree) $parentstr < ../message > ../map/$commit ||
344 die "could not write rewritten commit"
345done <../revs
346
347# In case of a subdirectory filter, it is possible that a specified head
348# is not in the set of rewritten commits, because it was pruned by the
349# revision walker. Fix it by mapping these heads to the unique nearest
350# ancestor that survived the pruning.
351
352if test "$filter_subdir"
353then
354 while read ref
355 do
356 sha1=$(git rev-parse "$ref"^0)
357 test -f "$workdir"/../map/$sha1 && continue
358 ancestor=$(git rev-list --simplify-merges -1 \
359 $ref -- "$filter_subdir")
360 test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
361 done < "$tempdir"/heads
362fi
363
364# Finally update the refs
365
366_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
367_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
368echo
369while read ref
370do
371 # avoid rewriting a ref twice
372 test -f "$orig_namespace$ref" && continue
373
374 sha1=$(git rev-parse "$ref"^0)
375 rewritten=$(map $sha1)
376
377 test $sha1 = "$rewritten" &&
378 warn "WARNING: Ref '$ref' is unchanged" &&
379 continue
380
381 case "$rewritten" in
382 '')
383 echo "Ref '$ref' was deleted"
384 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
385 die "Could not delete $ref"
386 ;;
387 $_x40)
388 echo "Ref '$ref' was rewritten"
389 if ! git update-ref -m "filter-branch: rewrite" \
390 "$ref" $rewritten $sha1 2>/dev/null; then
391 if test $(git cat-file -t "$ref") = tag; then
392 if test -z "$filter_tag_name"; then
393 warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
394 warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
395 fi
396 else
397 die "Could not rewrite $ref"
398 fi
399 fi
400 ;;
401 *)
402 # NEEDSWORK: possibly add -Werror, making this an error
403 warn "WARNING: '$ref' was rewritten into multiple commits:"
404 warn "$rewritten"
405 warn "WARNING: Ref '$ref' points to the first one now."
406 rewritten=$(echo "$rewritten" | head -n 1)
407 git update-ref -m "filter-branch: rewrite to first" \
408 "$ref" $rewritten $sha1 ||
409 die "Could not rewrite $ref"
410 ;;
411 esac
412 git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
413 exit
414done < "$tempdir"/heads
415
416# TODO: This should possibly go, with the semantics that all positive given
417# refs are updated, and their original heads stored in refs/original/
418# Filter tags
419
420if [ "$filter_tag_name" ]; then
421 git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
422 while read sha1 type ref; do
423 ref="${ref#refs/tags/}"
424 # XXX: Rewrite tagged trees as well?
425 if [ "$type" != "commit" -a "$type" != "tag" ]; then
426 continue;
427 fi
428
429 if [ "$type" = "tag" ]; then
430 # Dereference to a commit
431 sha1t="$sha1"
432 sha1="$(git rev-parse -q "$sha1"^{commit})" || continue
433 fi
434
435 [ -f "../map/$sha1" ] || continue
436 new_sha1="$(cat "../map/$sha1")"
437 GIT_COMMIT="$sha1"
438 export GIT_COMMIT
439 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
440 die "tag name filter failed: $filter_tag_name"
441
442 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
443
444 if [ "$type" = "tag" ]; then
445 new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
446 "$new_sha1" "$new_ref"
447 git cat-file tag "$ref" |
448 sed -n \
449 -e "1,/^$/{
450 /^object /d
451 /^type /d
452 /^tag /d
453 }" \
454 -e '/^-----BEGIN PGP SIGNATURE-----/q' \
455 -e 'p' ) |
456 git mktag) ||
457 die "Could not create new tag object for $ref"
458 if git cat-file tag "$ref" | \
459 sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
460 then
461 warn "gpg signature stripped from tag object $sha1t"
462 fi
463 fi
464
465 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
466 die "Could not write tag $new_ref"
467 done
468fi
469
470cd ../..
471rm -rf "$tempdir"
472
473trap - 0
474
475unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
476test -z "$ORIG_GIT_DIR" || {
477 GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
478}
479test -z "$ORIG_GIT_WORK_TREE" || {
480 GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
481 export GIT_WORK_TREE
482}
483test -z "$ORIG_GIT_INDEX_FILE" || {
484 GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
485 export GIT_INDEX_FILE
486}
487
488if [ "$(is_bare_repository)" = false ]; then
489 git read-tree -u -m HEAD || exit
490fi
491
492exit 0