Merge branch 'tb/reverse-midx'
[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_$1_DATE"
78 }
79
80 set_ident () {
81         parse_ident_from_commit author AUTHOR committer COMMITTER
82         finish_ident AUTHOR
83         finish_ident COMMITTER
84 }
85
86 if test -z "$FILTER_BRANCH_SQUELCH_WARNING$GIT_TEST_DISALLOW_ABBREVIATED_OPTIONS"
87 then
88         cat <<EOF
89 WARNING: git-filter-branch has a glut of gotchas generating mangled history
90          rewrites.  Hit Ctrl-C before proceeding to abort, then use an
91          alternative filtering tool such as 'git filter-repo'
92          (https://github.com/newren/git-filter-repo/) instead.  See the
93          filter-branch manual page for more details; to squelch this warning,
94          set FILTER_BRANCH_SQUELCH_WARNING=1.
95 EOF
96         sleep 10
97         printf "Proceeding with filter-branch...\n\n"
98 fi
99
100 USAGE="[--setup <command>] [--subdirectory-filter <directory>] [--env-filter <command>]
101         [--tree-filter <command>] [--index-filter <command>]
102         [--parent-filter <command>] [--msg-filter <command>]
103         [--commit-filter <command>] [--tag-name-filter <command>]
104         [--original <namespace>]
105         [-d <directory>] [-f | --force] [--state-branch <branch>]
106         [--] [<rev-list options>...]"
107
108 OPTIONS_SPEC=
109 . git-sh-setup
110
111 if [ "$(is_bare_repository)" = false ]; then
112         require_clean_work_tree 'rewrite branches'
113 fi
114
115 tempdir=.git-rewrite
116 filter_setup=
117 filter_env=
118 filter_tree=
119 filter_index=
120 filter_parent=
121 filter_msg=cat
122 filter_commit=
123 filter_tag_name=
124 filter_subdir=
125 state_branch=
126 orig_namespace=refs/original/
127 force=
128 prune_empty=
129 remap_to_ancestor=
130 while :
131 do
132         case "$1" in
133         --)
134                 shift
135                 break
136                 ;;
137         --force|-f)
138                 shift
139                 force=t
140                 continue
141                 ;;
142         --remap-to-ancestor)
143                 # deprecated ($remap_to_ancestor is set now automatically)
144                 shift
145                 remap_to_ancestor=t
146                 continue
147                 ;;
148         --prune-empty)
149                 shift
150                 prune_empty=t
151                 continue
152                 ;;
153         -*)
154                 ;;
155         *)
156                 break;
157         esac
158
159         # all switches take one argument
160         ARG="$1"
161         case "$#" in 1) usage ;; esac
162         shift
163         OPTARG="$1"
164         shift
165
166         case "$ARG" in
167         -d)
168                 tempdir="$OPTARG"
169                 ;;
170         --setup)
171                 filter_setup="$OPTARG"
172                 ;;
173         --subdirectory-filter)
174                 filter_subdir="$OPTARG"
175                 remap_to_ancestor=t
176                 ;;
177         --env-filter)
178                 filter_env="$OPTARG"
179                 ;;
180         --tree-filter)
181                 filter_tree="$OPTARG"
182                 ;;
183         --index-filter)
184                 filter_index="$OPTARG"
185                 ;;
186         --parent-filter)
187                 filter_parent="$OPTARG"
188                 ;;
189         --msg-filter)
190                 filter_msg="$OPTARG"
191                 ;;
192         --commit-filter)
193                 filter_commit="$functions; $OPTARG"
194                 ;;
195         --tag-name-filter)
196                 filter_tag_name="$OPTARG"
197                 ;;
198         --original)
199                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
200                 ;;
201         --state-branch)
202                 state_branch="$OPTARG"
203                 ;;
204         *)
205                 usage
206                 ;;
207         esac
208 done
209
210 case "$prune_empty,$filter_commit" in
211 ,)
212         filter_commit='git commit-tree "$@"';;
213 t,)
214         filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
215 ,*)
216         ;;
217 *)
218         die "Cannot set --prune-empty and --commit-filter at the same time"
219 esac
220
221 case "$force" in
222 t)
223         rm -rf "$tempdir"
224 ;;
225 '')
226         test -d "$tempdir" &&
227                 die "$tempdir already exists, please remove it"
228 esac
229 orig_dir=$(pwd)
230 mkdir -p "$tempdir/t" &&
231 tempdir="$(cd "$tempdir"; pwd)" &&
232 cd "$tempdir/t" &&
233 workdir="$(pwd)" ||
234 die ""
235
236 # Remove tempdir on exit
237 trap 'cd "$orig_dir"; rm -rf "$tempdir"' 0
238
239 ORIG_GIT_DIR="$GIT_DIR"
240 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
241 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
242 ORIG_GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME"
243 ORIG_GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL"
244 ORIG_GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE"
245 ORIG_GIT_COMMITTER_NAME="$GIT_COMMITTER_NAME"
246 ORIG_GIT_COMMITTER_EMAIL="$GIT_COMMITTER_EMAIL"
247 ORIG_GIT_COMMITTER_DATE="$GIT_COMMITTER_DATE"
248
249 GIT_WORK_TREE=.
250 export GIT_DIR GIT_WORK_TREE
251
252 # Make sure refs/original is empty
253 git for-each-ref > "$tempdir"/backup-refs || exit
254 while read sha1 type name
255 do
256         case "$force,$name" in
257         ,$orig_namespace*)
258                 die "Cannot create a new backup.
259 A previous backup already exists in $orig_namespace
260 Force overwriting the backup with -f"
261         ;;
262         t,$orig_namespace*)
263                 git update-ref -d "$name" $sha1
264         ;;
265         esac
266 done < "$tempdir"/backup-refs
267
268 # The refs should be updated if their heads were rewritten
269 git rev-parse --no-flags --revs-only --symbolic-full-name \
270         --default HEAD "$@" > "$tempdir"/raw-refs || exit
271 while read ref
272 do
273         case "$ref" in ^?*) continue ;; esac
274
275         if git rev-parse --verify "$ref"^0 >/dev/null 2>&1
276         then
277                 echo "$ref"
278         else
279                 warn "WARNING: not rewriting '$ref' (not a committish)"
280         fi
281 done >"$tempdir"/heads <"$tempdir"/raw-refs
282
283 test -s "$tempdir"/heads ||
284         die "You must specify a ref to rewrite."
285
286 GIT_INDEX_FILE="$(pwd)/../index"
287 export GIT_INDEX_FILE
288
289 # map old->new commit ids for rewriting parents
290 mkdir ../map || die "Could not create map/ directory"
291
292 if test -n "$state_branch"
293 then
294         state_commit=$(git rev-parse --no-flags --revs-only "$state_branch")
295         if test -n "$state_commit"
296         then
297                 echo "Populating map from $state_branch ($state_commit)" 1>&2
298                 perl -e'open(MAP, "-|", "git show $ARGV[0]:filter.map") or die;
299                         while (<MAP>) {
300                                 m/(.*):(.*)/ or die;
301                                 open F, ">../map/$1" or die;
302                                 print F "$2" or die;
303                                 close(F) or die;
304                         }
305                         close(MAP) or die;' "$state_commit" \
306                                 || die "Unable to load state from $state_branch:filter.map"
307         else
308                 echo "Branch $state_branch does not exist. Will create" 1>&2
309         fi
310 fi
311
312 # we need "--" only if there are no path arguments in $@
313 nonrevs=$(git rev-parse --no-revs "$@") || exit
314 if test -z "$nonrevs"
315 then
316         dashdash=--
317 else
318         dashdash=
319         remap_to_ancestor=t
320 fi
321
322 git rev-parse --revs-only "$@" >../parse
323
324 case "$filter_subdir" in
325 "")
326         eval set -- "$(git rev-parse --sq --no-revs "$@")"
327         ;;
328 *)
329         eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
330                 "$filter_subdir")"
331         ;;
332 esac
333
334 git rev-list --reverse --topo-order --default HEAD \
335         --parents --simplify-merges --stdin "$@" <../parse >../revs ||
336         die "Could not get the commits"
337 commits=$(wc -l <../revs | tr -d " ")
338
339 test $commits -eq 0 && die_with_status 2 "Found nothing to rewrite"
340
341 # Rewrite the commits
342 report_progress ()
343 {
344         if test -n "$progress" &&
345                 test $git_filter_branch__commit_count -gt $next_sample_at
346         then
347                 count=$git_filter_branch__commit_count
348
349                 now=$(date +%s)
350                 elapsed=$(($now - $start_timestamp))
351                 remaining=$(( ($commits - $count) * $elapsed / $count ))
352                 if test $elapsed -gt 0
353                 then
354                         next_sample_at=$(( ($elapsed + 1) * $count / $elapsed ))
355                 else
356                         next_sample_at=$(($next_sample_at + 1))
357                 fi
358                 progress=" ($elapsed seconds passed, remaining $remaining predicted)"
359         fi
360         printf "\rRewrite $commit ($count/$commits)$progress    "
361 }
362
363 git_filter_branch__commit_count=0
364
365 progress= start_timestamp=
366 if date '+%s' 2>/dev/null | grep -q '^[0-9][0-9]*$'
367 then
368         next_sample_at=0
369         progress="dummy to ensure this is not empty"
370         start_timestamp=$(date '+%s')
371 fi
372
373 if test -n "$filter_index" ||
374    test -n "$filter_tree" ||
375    test -n "$filter_subdir"
376 then
377         need_index=t
378 else
379         need_index=
380 fi
381
382 eval "$filter_setup" < /dev/null ||
383         die "filter setup failed: $filter_setup"
384
385 while read commit parents; do
386         git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
387
388         report_progress
389         test -f "$workdir"/../map/$commit && continue
390
391         case "$filter_subdir" in
392         "")
393                 if test -n "$need_index"
394                 then
395                         GIT_ALLOW_NULL_SHA1=1 git read-tree -i -m $commit
396                 fi
397                 ;;
398         *)
399                 # The commit may not have the subdirectory at all
400                 err=$(GIT_ALLOW_NULL_SHA1=1 \
401                       git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
402                         if ! git rev-parse -q --verify $commit:"$filter_subdir"
403                         then
404                                 rm -f "$GIT_INDEX_FILE"
405                         else
406                                 echo >&2 "$err"
407                                 false
408                         fi
409                 }
410         esac || die "Could not initialize the index"
411
412         GIT_COMMIT=$commit
413         export GIT_COMMIT
414         git cat-file commit "$commit" >../commit ||
415                 die "Cannot read commit $commit"
416
417         eval "$(set_ident <../commit)" ||
418                 die "setting author/committer failed for commit $commit"
419         eval "$filter_env" < /dev/null ||
420                 die "env filter failed: $filter_env"
421
422         if [ "$filter_tree" ]; then
423                 git checkout-index -f -u -a ||
424                         die "Could not checkout the index"
425                 # files that $commit removed are now still in the working tree;
426                 # remove them, else they would be added again
427                 git clean -d -q -f -x
428                 eval "$filter_tree" < /dev/null ||
429                         die "tree filter failed: $filter_tree"
430
431                 (
432                         git diff-index -r --name-only --ignore-submodules $commit -- &&
433                         git ls-files --others
434                 ) > "$tempdir"/tree-state || exit
435                 git update-index --add --replace --remove --stdin \
436                         < "$tempdir"/tree-state || exit
437         fi
438
439         eval "$filter_index" < /dev/null ||
440                 die "index filter failed: $filter_index"
441
442         parentstr=
443         for parent in $parents; do
444                 for reparent in $(map "$parent"); do
445                         case "$parentstr " in
446                         *" -p $reparent "*)
447                                 ;;
448                         *)
449                                 parentstr="$parentstr -p $reparent"
450                                 ;;
451                         esac
452                 done
453         done
454         if [ "$filter_parent" ]; then
455                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
456                                 die "parent filter failed: $filter_parent"
457         fi
458
459         {
460                 while IFS='' read -r header_line && test -n "$header_line"
461                 do
462                         # skip header lines...
463                         :;
464                 done
465                 # and output the actual commit message
466                 cat
467         } <../commit |
468                 eval "$filter_msg" > ../message ||
469                         die "msg filter failed: $filter_msg"
470
471         if test -n "$need_index"
472         then
473                 tree=$(git write-tree)
474         else
475                 tree=$(git rev-parse "$commit^{tree}")
476         fi
477         workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
478                 "$tree" $parentstr < ../message > ../map/$commit ||
479                         die "could not write rewritten commit"
480 done <../revs
481
482 # If we are filtering for paths, as in the case of a subdirectory
483 # filter, it is possible that a specified head is not in the set of
484 # rewritten commits, because it was pruned by the revision walker.
485 # Ancestor remapping fixes this by mapping these heads to the unique
486 # nearest ancestor that survived the pruning.
487
488 if test "$remap_to_ancestor" = t
489 then
490         while read ref
491         do
492                 sha1=$(git rev-parse "$ref"^0)
493                 test -f "$workdir"/../map/$sha1 && continue
494                 ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
495                 test "$ancestor" && echo $(map $ancestor) >"$workdir"/../map/$sha1
496         done < "$tempdir"/heads
497 fi
498
499 # Finally update the refs
500
501 echo
502 while read ref
503 do
504         # avoid rewriting a ref twice
505         test -f "$orig_namespace$ref" && continue
506
507         sha1=$(git rev-parse "$ref"^0)
508         rewritten=$(map $sha1)
509
510         test $sha1 = "$rewritten" &&
511                 warn "WARNING: Ref '$ref' is unchanged" &&
512                 continue
513
514         case "$rewritten" in
515         '')
516                 echo "Ref '$ref' was deleted"
517                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
518                         die "Could not delete $ref"
519         ;;
520         *)
521                 echo "Ref '$ref' was rewritten"
522                 if ! git update-ref -m "filter-branch: rewrite" \
523                                         "$ref" $rewritten $sha1 2>/dev/null; then
524                         if test $(git cat-file -t "$ref") = tag; then
525                                 if test -z "$filter_tag_name"; then
526                                         warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
527                                         warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
528                                 fi
529                         else
530                                 die "Could not rewrite $ref"
531                         fi
532                 fi
533         ;;
534         esac
535         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
536                  exit
537 done < "$tempdir"/heads
538
539 # TODO: This should possibly go, with the semantics that all positive given
540 #       refs are updated, and their original heads stored in refs/original/
541 # Filter tags
542
543 if [ "$filter_tag_name" ]; then
544         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
545         while read sha1 type ref; do
546                 ref="${ref#refs/tags/}"
547                 # XXX: Rewrite tagged trees as well?
548                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
549                         continue;
550                 fi
551
552                 if [ "$type" = "tag" ]; then
553                         # Dereference to a commit
554                         sha1t="$sha1"
555                         sha1="$(git rev-parse -q "$sha1"^{commit})" || continue
556                 fi
557
558                 [ -f "../map/$sha1" ] || continue
559                 new_sha1="$(cat "../map/$sha1")"
560                 GIT_COMMIT="$sha1"
561                 export GIT_COMMIT
562                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
563                         die "tag name filter failed: $filter_tag_name"
564
565                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
566
567                 if [ "$type" = "tag" ]; then
568                         new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
569                                                 "$new_sha1" "$new_ref"
570                                 git cat-file tag "$ref" |
571                                 sed -n \
572                                     -e '1,/^$/{
573                                           /^object /d
574                                           /^type /d
575                                           /^tag /d
576                                         }' \
577                                     -e '/^-----BEGIN PGP SIGNATURE-----/q' \
578                                     -e 'p' ) |
579                                 git hash-object -t tag -w --stdin) ||
580                                 die "Could not create new tag object for $ref"
581                         if git cat-file tag "$ref" | \
582                            sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
583                         then
584                                 warn "gpg signature stripped from tag object $sha1t"
585                         fi
586                 fi
587
588                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
589                         die "Could not write tag $new_ref"
590         done
591 fi
592
593 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
594 unset GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
595 unset GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL GIT_COMMITTER_DATE
596 test -z "$ORIG_GIT_DIR" || {
597         GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
598 }
599 test -z "$ORIG_GIT_WORK_TREE" || {
600         GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
601         export GIT_WORK_TREE
602 }
603 test -z "$ORIG_GIT_INDEX_FILE" || {
604         GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
605         export GIT_INDEX_FILE
606 }
607 test -z "$ORIG_GIT_AUTHOR_NAME" || {
608         GIT_AUTHOR_NAME="$ORIG_GIT_AUTHOR_NAME" &&
609         export GIT_AUTHOR_NAME
610 }
611 test -z "$ORIG_GIT_AUTHOR_EMAIL" || {
612         GIT_AUTHOR_EMAIL="$ORIG_GIT_AUTHOR_EMAIL" &&
613         export GIT_AUTHOR_EMAIL
614 }
615 test -z "$ORIG_GIT_AUTHOR_DATE" || {
616         GIT_AUTHOR_DATE="$ORIG_GIT_AUTHOR_DATE" &&
617         export GIT_AUTHOR_DATE
618 }
619 test -z "$ORIG_GIT_COMMITTER_NAME" || {
620         GIT_COMMITTER_NAME="$ORIG_GIT_COMMITTER_NAME" &&
621         export GIT_COMMITTER_NAME
622 }
623 test -z "$ORIG_GIT_COMMITTER_EMAIL" || {
624         GIT_COMMITTER_EMAIL="$ORIG_GIT_COMMITTER_EMAIL" &&
625         export GIT_COMMITTER_EMAIL
626 }
627 test -z "$ORIG_GIT_COMMITTER_DATE" || {
628         GIT_COMMITTER_DATE="$ORIG_GIT_COMMITTER_DATE" &&
629         export GIT_COMMITTER_DATE
630 }
631
632 if test -n "$state_branch"
633 then
634         echo "Saving rewrite state to $state_branch" 1>&2
635         state_blob=$(
636                 perl -e'opendir D, "../map" or die;
637                         open H, "|-", "git hash-object -w --stdin" or die;
638                         foreach (sort readdir(D)) {
639                                 next if m/^\.\.?$/;
640                                 open F, "<../map/$_" or die;
641                                 chomp($f = <F>);
642                                 print H "$_:$f\n" or die;
643                         }
644                         close(H) or die;' || die "Unable to save state")
645         state_tree=$(printf '100644 blob %s\tfilter.map\n' "$state_blob" | git mktree)
646         if test -n "$state_commit"
647         then
648                 state_commit=$(echo "Sync" | git commit-tree "$state_tree" -p "$state_commit")
649         else
650                 state_commit=$(echo "Sync" | git commit-tree "$state_tree" )
651         fi
652         git update-ref "$state_branch" "$state_commit"
653 fi
654
655 cd "$orig_dir"
656 rm -rf "$tempdir"
657
658 trap - 0
659
660 if [ "$(is_bare_repository)" = false ]; then
661         git read-tree -u -m HEAD || exit
662 fi
663
664 exit 0