Merge branch 'js/rebase-i-root-fix'
[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 # The following functions will also be available in the commit filter:
12
13 functions=$(cat << \EOF
14 EMPTY_TREE=$(git hash-object -t tree /dev/null)
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 "$1"
28         fi
29 }
30
31 # if you run 'skip_commit "$@"' in a commit filter, it will print
32 # the (mapped) parents, effectively skipping the commit.
33
34 skip_commit()
35 {
36         shift;
37         while [ -n "$1" ];
38         do
39                 shift;
40                 map "$1";
41                 shift;
42         done;
43 }
44
45 # if you run 'git_commit_non_empty_tree "$@"' in a commit filter,
46 # it will skip commits that leave the tree untouched, commit the other.
47 git_commit_non_empty_tree()
48 {
49         if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
50                 map "$3"
51         elif test $# = 1 && test "$1" = $EMPTY_TREE; then
52                 :
53         else
54                 git commit-tree "$@"
55         fi
56 }
57 # override die(): this version puts in an extra line break, so that
58 # the progress is still visible
59
60 die()
61 {
62         echo >&2
63         echo "$*" >&2
64         exit 1
65 }
66 EOF
67 )
68
69 eval "$functions"
70
71 finish_ident() {
72         # Ensure non-empty id name.
73         echo "case \"\$GIT_$1_NAME\" in \"\") GIT_$1_NAME=\"\${GIT_$1_EMAIL%%@*}\" && export GIT_$1_NAME;; esac"
74         # And make sure everything is exported.
75         echo "export GIT_$1_NAME"
76         echo "export GIT_$1_EMAIL"
77         echo "export GIT_$1_DATE"
78 }
79
80 set_ident () {
81         parse_ident_from_commit author AUTHOR committer COMMITTER
82         finish_ident AUTHOR
83         finish_ident COMMITTER
84 }
85
86 USAGE="[--setup <command>] [--subdirectory-filter <directory>] [--env-filter <command>]
87         [--tree-filter <command>] [--index-filter <command>]
88         [--parent-filter <command>] [--msg-filter <command>]
89         [--commit-filter <command>] [--tag-name-filter <command>]
90         [--original <namespace>]
91         [-d <directory>] [-f | --force] [--state-branch <branch>]
92         [--] [<rev-list options>...]"
93
94 OPTIONS_SPEC=
95 . git-sh-setup
96
97 if [ "$(is_bare_repository)" = false ]; then
98         require_clean_work_tree 'rewrite branches'
99 fi
100
101 tempdir=.git-rewrite
102 filter_setup=
103 filter_env=
104 filter_tree=
105 filter_index=
106 filter_parent=
107 filter_msg=cat
108 filter_commit=
109 filter_tag_name=
110 filter_subdir=
111 state_branch=
112 orig_namespace=refs/original/
113 force=
114 prune_empty=
115 remap_to_ancestor=
116 while :
117 do
118         case "$1" in
119         --)
120                 shift
121                 break
122                 ;;
123         --force|-f)
124                 shift
125                 force=t
126                 continue
127                 ;;
128         --remap-to-ancestor)
129                 # deprecated ($remap_to_ancestor is set now automatically)
130                 shift
131                 remap_to_ancestor=t
132                 continue
133                 ;;
134         --prune-empty)
135                 shift
136                 prune_empty=t
137                 continue
138                 ;;
139         -*)
140                 ;;
141         *)
142                 break;
143         esac
144
145         # all switches take one argument
146         ARG="$1"
147         case "$#" in 1) usage ;; esac
148         shift
149         OPTARG="$1"
150         shift
151
152         case "$ARG" in
153         -d)
154                 tempdir="$OPTARG"
155                 ;;
156         --setup)
157                 filter_setup="$OPTARG"
158                 ;;
159         --subdirectory-filter)
160                 filter_subdir="$OPTARG"
161                 remap_to_ancestor=t
162                 ;;
163         --env-filter)
164                 filter_env="$OPTARG"
165                 ;;
166         --tree-filter)
167                 filter_tree="$OPTARG"
168                 ;;
169         --index-filter)
170                 filter_index="$OPTARG"
171                 ;;
172         --parent-filter)
173                 filter_parent="$OPTARG"
174                 ;;
175         --msg-filter)
176                 filter_msg="$OPTARG"
177                 ;;
178         --commit-filter)
179                 filter_commit="$functions; $OPTARG"
180                 ;;
181         --tag-name-filter)
182                 filter_tag_name="$OPTARG"
183                 ;;
184         --original)
185                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
186                 ;;
187         --state-branch)
188                 state_branch="$OPTARG"
189                 ;;
190         *)
191                 usage
192                 ;;
193         esac
194 done
195
196 case "$prune_empty,$filter_commit" in
197 ,)
198         filter_commit='git commit-tree "$@"';;
199 t,)
200         filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
201 ,*)
202         ;;
203 *)
204         die "Cannot set --prune-empty and --commit-filter at the same time"
205 esac
206
207 case "$force" in
208 t)
209         rm -rf "$tempdir"
210 ;;
211 '')
212         test -d "$tempdir" &&
213                 die "$tempdir already exists, please remove it"
214 esac
215 orig_dir=$(pwd)
216 mkdir -p "$tempdir/t" &&
217 tempdir="$(cd "$tempdir"; pwd)" &&
218 cd "$tempdir/t" &&
219 workdir="$(pwd)" ||
220 die ""
221
222 # Remove tempdir on exit
223 trap 'cd "$orig_dir"; rm -rf "$tempdir"' 0
224
225 ORIG_GIT_DIR="$GIT_DIR"
226 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
227 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
228 ORIG_GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME"
229 ORIG_GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL"
230 ORIG_GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE"
231 ORIG_GIT_COMMITTER_NAME="$GIT_COMMITTER_NAME"
232 ORIG_GIT_COMMITTER_EMAIL="$GIT_COMMITTER_EMAIL"
233 ORIG_GIT_COMMITTER_DATE="$GIT_COMMITTER_DATE"
234
235 GIT_WORK_TREE=.
236 export GIT_DIR GIT_WORK_TREE
237
238 # Make sure refs/original is empty
239 git for-each-ref > "$tempdir"/backup-refs || exit
240 while read sha1 type name
241 do
242         case "$force,$name" in
243         ,$orig_namespace*)
244                 die "Cannot create a new backup.
245 A previous backup already exists in $orig_namespace
246 Force overwriting the backup with -f"
247         ;;
248         t,$orig_namespace*)
249                 git update-ref -d "$name" $sha1
250         ;;
251         esac
252 done < "$tempdir"/backup-refs
253
254 # The refs should be updated if their heads were rewritten
255 git rev-parse --no-flags --revs-only --symbolic-full-name \
256         --default HEAD "$@" > "$tempdir"/raw-refs || exit
257 while read ref
258 do
259         case "$ref" in ^?*) continue ;; esac
260
261         if git rev-parse --verify "$ref"^0 >/dev/null 2>&1
262         then
263                 echo "$ref"
264         else
265                 warn "WARNING: not rewriting '$ref' (not a committish)"
266         fi
267 done >"$tempdir"/heads <"$tempdir"/raw-refs
268
269 test -s "$tempdir"/heads ||
270         die "You must specify a ref to rewrite."
271
272 GIT_INDEX_FILE="$(pwd)/../index"
273 export GIT_INDEX_FILE
274
275 # map old->new commit ids for rewriting parents
276 mkdir ../map || die "Could not create map/ directory"
277
278 if test -n "$state_branch"
279 then
280         state_commit=$(git rev-parse --no-flags --revs-only "$state_branch")
281         if test -n "$state_commit"
282         then
283                 echo "Populating map from $state_branch ($state_commit)" 1>&2
284                 perl -e'open(MAP, "-|", "git show $ARGV[0]:filter.map") or die;
285                         while (<MAP>) {
286                                 m/(.*):(.*)/ or die;
287                                 open F, ">../map/$1" or die;
288                                 print F "$2" or die;
289                                 close(F) or die;
290                         }
291                         close(MAP) or die;' "$state_commit" \
292                                 || die "Unable to load state from $state_branch:filter.map"
293         else
294                 echo "Branch $state_branch does not exist. Will create" 1>&2
295         fi
296 fi
297
298 # we need "--" only if there are no path arguments in $@
299 nonrevs=$(git rev-parse --no-revs "$@") || exit
300 if test -z "$nonrevs"
301 then
302         dashdash=--
303 else
304         dashdash=
305         remap_to_ancestor=t
306 fi
307
308 git rev-parse --revs-only "$@" >../parse
309
310 case "$filter_subdir" in
311 "")
312         eval set -- "$(git rev-parse --sq --no-revs "$@")"
313         ;;
314 *)
315         eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
316                 "$filter_subdir")"
317         ;;
318 esac
319
320 git rev-list --reverse --topo-order --default HEAD \
321         --parents --simplify-merges --stdin "$@" <../parse >../revs ||
322         die "Could not get the commits"
323 commits=$(wc -l <../revs | tr -d " ")
324
325 test $commits -eq 0 && die_with_status 2 "Found nothing to rewrite"
326
327 # Rewrite the commits
328 report_progress ()
329 {
330         if test -n "$progress" &&
331                 test $git_filter_branch__commit_count -gt $next_sample_at
332         then
333                 count=$git_filter_branch__commit_count
334
335                 now=$(date +%s)
336                 elapsed=$(($now - $start_timestamp))
337                 remaining=$(( ($commits - $count) * $elapsed / $count ))
338                 if test $elapsed -gt 0
339                 then
340                         next_sample_at=$(( ($elapsed + 1) * $count / $elapsed ))
341                 else
342                         next_sample_at=$(($next_sample_at + 1))
343                 fi
344                 progress=" ($elapsed seconds passed, remaining $remaining predicted)"
345         fi
346         printf "\rRewrite $commit ($count/$commits)$progress    "
347 }
348
349 git_filter_branch__commit_count=0
350
351 progress= start_timestamp=
352 if date '+%s' 2>/dev/null | grep -q '^[0-9][0-9]*$'
353 then
354         next_sample_at=0
355         progress="dummy to ensure this is not empty"
356         start_timestamp=$(date '+%s')
357 fi
358
359 if test -n "$filter_index" ||
360    test -n "$filter_tree" ||
361    test -n "$filter_subdir"
362 then
363         need_index=t
364 else
365         need_index=
366 fi
367
368 eval "$filter_setup" < /dev/null ||
369         die "filter setup failed: $filter_setup"
370
371 while read commit parents; do
372         git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
373
374         report_progress
375
376         case "$filter_subdir" in
377         "")
378                 if test -n "$need_index"
379                 then
380                         GIT_ALLOW_NULL_SHA1=1 git read-tree -i -m $commit
381                 fi
382                 ;;
383         *)
384                 # The commit may not have the subdirectory at all
385                 err=$(GIT_ALLOW_NULL_SHA1=1 \
386                       git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
387                         if ! git rev-parse -q --verify $commit:"$filter_subdir"
388                         then
389                                 rm -f "$GIT_INDEX_FILE"
390                         else
391                                 echo >&2 "$err"
392                                 false
393                         fi
394                 }
395         esac || die "Could not initialize the index"
396
397         GIT_COMMIT=$commit
398         export GIT_COMMIT
399         git cat-file commit "$commit" >../commit ||
400                 die "Cannot read commit $commit"
401
402         eval "$(set_ident <../commit)" ||
403                 die "setting author/committer failed for commit $commit"
404         eval "$filter_env" < /dev/null ||
405                 die "env filter failed: $filter_env"
406
407         if [ "$filter_tree" ]; then
408                 git checkout-index -f -u -a ||
409                         die "Could not checkout the index"
410                 # files that $commit removed are now still in the working tree;
411                 # remove them, else they would be added again
412                 git clean -d -q -f -x
413                 eval "$filter_tree" < /dev/null ||
414                         die "tree filter failed: $filter_tree"
415
416                 (
417                         git diff-index -r --name-only --ignore-submodules $commit -- &&
418                         git ls-files --others
419                 ) > "$tempdir"/tree-state || exit
420                 git update-index --add --replace --remove --stdin \
421                         < "$tempdir"/tree-state || exit
422         fi
423
424         eval "$filter_index" < /dev/null ||
425                 die "index filter failed: $filter_index"
426
427         parentstr=
428         for parent in $parents; do
429                 for reparent in $(map "$parent"); do
430                         case "$parentstr " in
431                         *" -p $reparent "*)
432                                 ;;
433                         *)
434                                 parentstr="$parentstr -p $reparent"
435                                 ;;
436                         esac
437                 done
438         done
439         if [ "$filter_parent" ]; then
440                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
441                                 die "parent filter failed: $filter_parent"
442         fi
443
444         {
445                 while IFS='' read -r header_line && test -n "$header_line"
446                 do
447                         # skip header lines...
448                         :;
449                 done
450                 # and output the actual commit message
451                 cat
452         } <../commit |
453                 eval "$filter_msg" > ../message ||
454                         die "msg filter failed: $filter_msg"
455
456         if test -n "$need_index"
457         then
458                 tree=$(git write-tree)
459         else
460                 tree=$(git rev-parse "$commit^{tree}")
461         fi
462         workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
463                 "$tree" $parentstr < ../message > ../map/$commit ||
464                         die "could not write rewritten commit"
465 done <../revs
466
467 # If we are filtering for paths, as in the case of a subdirectory
468 # filter, it is possible that a specified head is not in the set of
469 # rewritten commits, because it was pruned by the revision walker.
470 # Ancestor remapping fixes this by mapping these heads to the unique
471 # nearest ancestor that survived the pruning.
472
473 if test "$remap_to_ancestor" = t
474 then
475         while read ref
476         do
477                 sha1=$(git rev-parse "$ref"^0)
478                 test -f "$workdir"/../map/$sha1 && continue
479                 ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
480                 test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
481         done < "$tempdir"/heads
482 fi
483
484 # Finally update the refs
485
486 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
487 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
488 echo
489 while read ref
490 do
491         # avoid rewriting a ref twice
492         test -f "$orig_namespace$ref" && continue
493
494         sha1=$(git rev-parse "$ref"^0)
495         rewritten=$(map $sha1)
496
497         test $sha1 = "$rewritten" &&
498                 warn "WARNING: Ref '$ref' is unchanged" &&
499                 continue
500
501         case "$rewritten" in
502         '')
503                 echo "Ref '$ref' was deleted"
504                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
505                         die "Could not delete $ref"
506         ;;
507         $_x40)
508                 echo "Ref '$ref' was rewritten"
509                 if ! git update-ref -m "filter-branch: rewrite" \
510                                         "$ref" $rewritten $sha1 2>/dev/null; then
511                         if test $(git cat-file -t "$ref") = tag; then
512                                 if test -z "$filter_tag_name"; then
513                                         warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
514                                         warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
515                                 fi
516                         else
517                                 die "Could not rewrite $ref"
518                         fi
519                 fi
520         ;;
521         *)
522                 # NEEDSWORK: possibly add -Werror, making this an error
523                 warn "WARNING: '$ref' was rewritten into multiple commits:"
524                 warn "$rewritten"
525                 warn "WARNING: Ref '$ref' points to the first one now."
526                 rewritten=$(echo "$rewritten" | head -n 1)
527                 git update-ref -m "filter-branch: rewrite to first" \
528                                 "$ref" $rewritten $sha1 ||
529                         die "Could not rewrite $ref"
530         ;;
531         esac
532         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
533                  exit
534 done < "$tempdir"/heads
535
536 # TODO: This should possibly go, with the semantics that all positive given
537 #       refs are updated, and their original heads stored in refs/original/
538 # Filter tags
539
540 if [ "$filter_tag_name" ]; then
541         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
542         while read sha1 type ref; do
543                 ref="${ref#refs/tags/}"
544                 # XXX: Rewrite tagged trees as well?
545                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
546                         continue;
547                 fi
548
549                 if [ "$type" = "tag" ]; then
550                         # Dereference to a commit
551                         sha1t="$sha1"
552                         sha1="$(git rev-parse -q "$sha1"^{commit})" || continue
553                 fi
554
555                 [ -f "../map/$sha1" ] || continue
556                 new_sha1="$(cat "../map/$sha1")"
557                 GIT_COMMIT="$sha1"
558                 export GIT_COMMIT
559                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
560                         die "tag name filter failed: $filter_tag_name"
561
562                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
563
564                 if [ "$type" = "tag" ]; then
565                         new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
566                                                 "$new_sha1" "$new_ref"
567                                 git cat-file tag "$ref" |
568                                 sed -n \
569                                     -e '1,/^$/{
570                                           /^object /d
571                                           /^type /d
572                                           /^tag /d
573                                         }' \
574                                     -e '/^-----BEGIN PGP SIGNATURE-----/q' \
575                                     -e 'p' ) |
576                                 git hash-object -t tag -w --stdin) ||
577                                 die "Could not create new tag object for $ref"
578                         if git cat-file tag "$ref" | \
579                            sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
580                         then
581                                 warn "gpg signature stripped from tag object $sha1t"
582                         fi
583                 fi
584
585                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
586                         die "Could not write tag $new_ref"
587         done
588 fi
589
590 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
591 unset GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
592 unset GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL GIT_COMMITTER_DATE
593 test -z "$ORIG_GIT_DIR" || {
594         GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
595 }
596 test -z "$ORIG_GIT_WORK_TREE" || {
597         GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
598         export GIT_WORK_TREE
599 }
600 test -z "$ORIG_GIT_INDEX_FILE" || {
601         GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
602         export GIT_INDEX_FILE
603 }
604 test -z "$ORIG_GIT_AUTHOR_NAME" || {
605         GIT_AUTHOR_NAME="$ORIG_GIT_AUTHOR_NAME" &&
606         export GIT_AUTHOR_NAME
607 }
608 test -z "$ORIG_GIT_AUTHOR_EMAIL" || {
609         GIT_AUTHOR_EMAIL="$ORIG_GIT_AUTHOR_EMAIL" &&
610         export GIT_AUTHOR_EMAIL
611 }
612 test -z "$ORIG_GIT_AUTHOR_DATE" || {
613         GIT_AUTHOR_DATE="$ORIG_GIT_AUTHOR_DATE" &&
614         export GIT_AUTHOR_DATE
615 }
616 test -z "$ORIG_GIT_COMMITTER_NAME" || {
617         GIT_COMMITTER_NAME="$ORIG_GIT_COMMITTER_NAME" &&
618         export GIT_COMMITTER_NAME
619 }
620 test -z "$ORIG_GIT_COMMITTER_EMAIL" || {
621         GIT_COMMITTER_EMAIL="$ORIG_GIT_COMMITTER_EMAIL" &&
622         export GIT_COMMITTER_EMAIL
623 }
624 test -z "$ORIG_GIT_COMMITTER_DATE" || {
625         GIT_COMMITTER_DATE="$ORIG_GIT_COMMITTER_DATE" &&
626         export GIT_COMMITTER_DATE
627 }
628
629 if test -n "$state_branch"
630 then
631         echo "Saving rewrite state to $state_branch" 1>&2
632         state_blob=$(
633                 perl -e'opendir D, "../map" or die;
634                         open H, "|-", "git hash-object -w --stdin" or die;
635                         foreach (sort readdir(D)) {
636                                 next if m/^\.\.?$/;
637                                 open F, "<../map/$_" or die;
638                                 chomp($f = <F>);
639                                 print H "$_:$f\n" or die;
640                         }
641                         close(H) or die;' || die "Unable to save state")
642         state_tree=$(printf '100644 blob %s\tfilter.map\n' "$state_blob" | git mktree)
643         if test -n "$state_commit"
644         then
645                 state_commit=$(echo "Sync" | git commit-tree "$state_tree" -p "$state_commit")
646         else
647                 state_commit=$(echo "Sync" | git commit-tree "$state_tree" )
648         fi
649         git update-ref "$state_branch" "$state_commit"
650 fi
651
652 cd "$orig_dir"
653 rm -rf "$tempdir"
654
655 trap - 0
656
657 if [ "$(is_bare_repository)" = false ]; then
658         git read-tree -u -m HEAD || exit
659 fi
660
661 exit 0