Sync with Git 2.13.7
[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=$(cat << \EOF
14 warn () {
15         echo "$*" >&2
16 }
17
18 map()
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
32 skip_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.
45 git_commit_non_empty_tree()
46 {
47         if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
48                 map "$3"
49         elif test $# = 1 && test "$1" = 4b825dc642cb6eb9a060e54bf8d69288fbee4904; then
50                 :
51         else
52                 git commit-tree "$@"
53         fi
54 }
55 # override die(): this version puts in an extra line break, so that
56 # the progress is still visible
57
58 die()
59 {
60         echo >&2
61         echo "$*" >&2
62         exit 1
63 }
64 EOF
65 )
66
67 eval "$functions"
68
69 finish_ident() {
70         # Ensure non-empty id name.
71         echo "case \"\$GIT_$1_NAME\" in \"\") GIT_$1_NAME=\"\${GIT_$1_EMAIL%%@*}\" && export GIT_$1_NAME;; esac"
72         # And make sure everything is exported.
73         echo "export GIT_$1_NAME"
74         echo "export GIT_$1_EMAIL"
75         echo "export GIT_$1_DATE"
76 }
77
78 set_ident () {
79         parse_ident_from_commit author AUTHOR committer COMMITTER
80         finish_ident AUTHOR
81         finish_ident COMMITTER
82 }
83
84 USAGE="[--setup <command>] [--env-filter <command>]
85         [--tree-filter <command>] [--index-filter <command>]
86         [--parent-filter <command>] [--msg-filter <command>]
87         [--commit-filter <command>] [--tag-name-filter <command>]
88         [--subdirectory-filter <directory>] [--original <namespace>]
89         [-d <directory>] [-f | --force]
90         [--] [<rev-list options>...]"
91
92 OPTIONS_SPEC=
93 . git-sh-setup
94
95 if [ "$(is_bare_repository)" = false ]; then
96         require_clean_work_tree 'rewrite branches'
97 fi
98
99 tempdir=.git-rewrite
100 filter_setup=
101 filter_env=
102 filter_tree=
103 filter_index=
104 filter_parent=
105 filter_msg=cat
106 filter_commit=
107 filter_tag_name=
108 filter_subdir=
109 orig_namespace=refs/original/
110 force=
111 prune_empty=
112 remap_to_ancestor=
113 while :
114 do
115         case "$1" in
116         --)
117                 shift
118                 break
119                 ;;
120         --force|-f)
121                 shift
122                 force=t
123                 continue
124                 ;;
125         --remap-to-ancestor)
126                 # deprecated ($remap_to_ancestor is set now automatically)
127                 shift
128                 remap_to_ancestor=t
129                 continue
130                 ;;
131         --prune-empty)
132                 shift
133                 prune_empty=t
134                 continue
135                 ;;
136         -*)
137                 ;;
138         *)
139                 break;
140         esac
141
142         # all switches take one argument
143         ARG="$1"
144         case "$#" in 1) usage ;; esac
145         shift
146         OPTARG="$1"
147         shift
148
149         case "$ARG" in
150         -d)
151                 tempdir="$OPTARG"
152                 ;;
153         --setup)
154                 filter_setup="$OPTARG"
155                 ;;
156         --env-filter)
157                 filter_env="$OPTARG"
158                 ;;
159         --tree-filter)
160                 filter_tree="$OPTARG"
161                 ;;
162         --index-filter)
163                 filter_index="$OPTARG"
164                 ;;
165         --parent-filter)
166                 filter_parent="$OPTARG"
167                 ;;
168         --msg-filter)
169                 filter_msg="$OPTARG"
170                 ;;
171         --commit-filter)
172                 filter_commit="$functions; $OPTARG"
173                 ;;
174         --tag-name-filter)
175                 filter_tag_name="$OPTARG"
176                 ;;
177         --subdirectory-filter)
178                 filter_subdir="$OPTARG"
179                 remap_to_ancestor=t
180                 ;;
181         --original)
182                 orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
183                 ;;
184         *)
185                 usage
186                 ;;
187         esac
188 done
189
190 case "$prune_empty,$filter_commit" in
191 ,)
192         filter_commit='git commit-tree "$@"';;
193 t,)
194         filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
195 ,*)
196         ;;
197 *)
198         die "Cannot set --prune-empty and --commit-filter at the same time"
199 esac
200
201 case "$force" in
202 t)
203         rm -rf "$tempdir"
204 ;;
205 '')
206         test -d "$tempdir" &&
207                 die "$tempdir already exists, please remove it"
208 esac
209 orig_dir=$(pwd)
210 mkdir -p "$tempdir/t" &&
211 tempdir="$(cd "$tempdir"; pwd)" &&
212 cd "$tempdir/t" &&
213 workdir="$(pwd)" ||
214 die ""
215
216 # Remove tempdir on exit
217 trap 'cd "$orig_dir"; rm -rf "$tempdir"' 0
218
219 ORIG_GIT_DIR="$GIT_DIR"
220 ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
221 ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
222 GIT_WORK_TREE=.
223 export GIT_DIR GIT_WORK_TREE
224
225 # Make sure refs/original is empty
226 git for-each-ref > "$tempdir"/backup-refs || exit
227 while read sha1 type name
228 do
229         case "$force,$name" in
230         ,$orig_namespace*)
231                 die "Cannot create a new backup.
232 A previous backup already exists in $orig_namespace
233 Force overwriting the backup with -f"
234         ;;
235         t,$orig_namespace*)
236                 git update-ref -d "$name" $sha1
237         ;;
238         esac
239 done < "$tempdir"/backup-refs
240
241 # The refs should be updated if their heads were rewritten
242 git rev-parse --no-flags --revs-only --symbolic-full-name \
243         --default HEAD "$@" > "$tempdir"/raw-heads || exit
244 sed -e '/^^/d' "$tempdir"/raw-heads >"$tempdir"/heads
245
246 test -s "$tempdir"/heads ||
247         die "You must specify a ref to rewrite."
248
249 GIT_INDEX_FILE="$(pwd)/../index"
250 export GIT_INDEX_FILE
251
252 # map old->new commit ids for rewriting parents
253 mkdir ../map || die "Could not create map/ directory"
254
255 # we need "--" only if there are no path arguments in $@
256 nonrevs=$(git rev-parse --no-revs "$@") || exit
257 if test -z "$nonrevs"
258 then
259         dashdash=--
260 else
261         dashdash=
262         remap_to_ancestor=t
263 fi
264
265 git rev-parse --revs-only "$@" >../parse
266
267 case "$filter_subdir" in
268 "")
269         eval set -- "$(git rev-parse --sq --no-revs "$@")"
270         ;;
271 *)
272         eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
273                 "$filter_subdir")"
274         ;;
275 esac
276
277 git rev-list --reverse --topo-order --default HEAD \
278         --parents --simplify-merges --stdin "$@" <../parse >../revs ||
279         die "Could not get the commits"
280 commits=$(wc -l <../revs | tr -d " ")
281
282 test $commits -eq 0 && die "Found nothing to rewrite"
283
284 # Rewrite the commits
285 report_progress ()
286 {
287         if test -n "$progress" &&
288                 test $git_filter_branch__commit_count -gt $next_sample_at
289         then
290                 count=$git_filter_branch__commit_count
291
292                 now=$(date +%s)
293                 elapsed=$(($now - $start_timestamp))
294                 remaining=$(( ($commits - $count) * $elapsed / $count ))
295                 if test $elapsed -gt 0
296                 then
297                         next_sample_at=$(( ($elapsed + 1) * $count / $elapsed ))
298                 else
299                         next_sample_at=$(($next_sample_at + 1))
300                 fi
301                 progress=" ($elapsed seconds passed, remaining $remaining predicted)"
302         fi
303         printf "\rRewrite $commit ($count/$commits)$progress    "
304 }
305
306 git_filter_branch__commit_count=0
307
308 progress= start_timestamp=
309 if date '+%s' 2>/dev/null | grep -q '^[0-9][0-9]*$'
310 then
311         next_sample_at=0
312         progress="dummy to ensure this is not empty"
313         start_timestamp=$(date '+%s')
314 fi
315
316 if test -n "$filter_index" ||
317    test -n "$filter_tree" ||
318    test -n "$filter_subdir"
319 then
320         need_index=t
321 else
322         need_index=
323 fi
324
325 eval "$filter_setup" < /dev/null ||
326         die "filter setup failed: $filter_setup"
327
328 while read commit parents; do
329         git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
330
331         report_progress
332
333         case "$filter_subdir" in
334         "")
335                 if test -n "$need_index"
336                 then
337                         GIT_ALLOW_NULL_SHA1=1 git read-tree -i -m $commit
338                 fi
339                 ;;
340         *)
341                 # The commit may not have the subdirectory at all
342                 err=$(GIT_ALLOW_NULL_SHA1=1 \
343                       git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
344                         if ! git rev-parse -q --verify $commit:"$filter_subdir"
345                         then
346                                 rm -f "$GIT_INDEX_FILE"
347                         else
348                                 echo >&2 "$err"
349                                 false
350                         fi
351                 }
352         esac || die "Could not initialize the index"
353
354         GIT_COMMIT=$commit
355         export GIT_COMMIT
356         git cat-file commit "$commit" >../commit ||
357                 die "Cannot read commit $commit"
358
359         eval "$(set_ident <../commit)" ||
360                 die "setting author/committer failed for commit $commit"
361         eval "$filter_env" < /dev/null ||
362                 die "env filter failed: $filter_env"
363
364         if [ "$filter_tree" ]; then
365                 git checkout-index -f -u -a ||
366                         die "Could not checkout the index"
367                 # files that $commit removed are now still in the working tree;
368                 # remove them, else they would be added again
369                 git clean -d -q -f -x
370                 eval "$filter_tree" < /dev/null ||
371                         die "tree filter failed: $filter_tree"
372
373                 (
374                         git diff-index -r --name-only --ignore-submodules $commit -- &&
375                         git ls-files --others
376                 ) > "$tempdir"/tree-state || exit
377                 git update-index --add --replace --remove --stdin \
378                         < "$tempdir"/tree-state || exit
379         fi
380
381         eval "$filter_index" < /dev/null ||
382                 die "index filter failed: $filter_index"
383
384         parentstr=
385         for parent in $parents; do
386                 for reparent in $(map "$parent"); do
387                         case "$parentstr " in
388                         *" -p $reparent "*)
389                                 ;;
390                         *)
391                                 parentstr="$parentstr -p $reparent"
392                                 ;;
393                         esac
394                 done
395         done
396         if [ "$filter_parent" ]; then
397                 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
398                                 die "parent filter failed: $filter_parent"
399         fi
400
401         {
402                 while IFS='' read -r header_line && test -n "$header_line"
403                 do
404                         # skip header lines...
405                         :;
406                 done
407                 # and output the actual commit message
408                 cat
409         } <../commit |
410                 eval "$filter_msg" > ../message ||
411                         die "msg filter failed: $filter_msg"
412
413         if test -n "$need_index"
414         then
415                 tree=$(git write-tree)
416         else
417                 tree=$(git rev-parse "$commit^{tree}")
418         fi
419         workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
420                 "$tree" $parentstr < ../message > ../map/$commit ||
421                         die "could not write rewritten commit"
422 done <../revs
423
424 # If we are filtering for paths, as in the case of a subdirectory
425 # filter, it is possible that a specified head is not in the set of
426 # rewritten commits, because it was pruned by the revision walker.
427 # Ancestor remapping fixes this by mapping these heads to the unique
428 # nearest ancestor that survived the pruning.
429
430 if test "$remap_to_ancestor" = t
431 then
432         while read ref
433         do
434                 sha1=$(git rev-parse "$ref"^0)
435                 test -f "$workdir"/../map/$sha1 && continue
436                 ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
437                 test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
438         done < "$tempdir"/heads
439 fi
440
441 # Finally update the refs
442
443 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
444 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
445 echo
446 while read ref
447 do
448         # avoid rewriting a ref twice
449         test -f "$orig_namespace$ref" && continue
450
451         sha1=$(git rev-parse "$ref"^0)
452         rewritten=$(map $sha1)
453
454         test $sha1 = "$rewritten" &&
455                 warn "WARNING: Ref '$ref' is unchanged" &&
456                 continue
457
458         case "$rewritten" in
459         '')
460                 echo "Ref '$ref' was deleted"
461                 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
462                         die "Could not delete $ref"
463         ;;
464         $_x40)
465                 echo "Ref '$ref' was rewritten"
466                 if ! git update-ref -m "filter-branch: rewrite" \
467                                         "$ref" $rewritten $sha1 2>/dev/null; then
468                         if test $(git cat-file -t "$ref") = tag; then
469                                 if test -z "$filter_tag_name"; then
470                                         warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
471                                         warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
472                                 fi
473                         else
474                                 die "Could not rewrite $ref"
475                         fi
476                 fi
477         ;;
478         *)
479                 # NEEDSWORK: possibly add -Werror, making this an error
480                 warn "WARNING: '$ref' was rewritten into multiple commits:"
481                 warn "$rewritten"
482                 warn "WARNING: Ref '$ref' points to the first one now."
483                 rewritten=$(echo "$rewritten" | head -n 1)
484                 git update-ref -m "filter-branch: rewrite to first" \
485                                 "$ref" $rewritten $sha1 ||
486                         die "Could not rewrite $ref"
487         ;;
488         esac
489         git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1 ||
490                  exit
491 done < "$tempdir"/heads
492
493 # TODO: This should possibly go, with the semantics that all positive given
494 #       refs are updated, and their original heads stored in refs/original/
495 # Filter tags
496
497 if [ "$filter_tag_name" ]; then
498         git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
499         while read sha1 type ref; do
500                 ref="${ref#refs/tags/}"
501                 # XXX: Rewrite tagged trees as well?
502                 if [ "$type" != "commit" -a "$type" != "tag" ]; then
503                         continue;
504                 fi
505
506                 if [ "$type" = "tag" ]; then
507                         # Dereference to a commit
508                         sha1t="$sha1"
509                         sha1="$(git rev-parse -q "$sha1"^{commit})" || continue
510                 fi
511
512                 [ -f "../map/$sha1" ] || continue
513                 new_sha1="$(cat "../map/$sha1")"
514                 GIT_COMMIT="$sha1"
515                 export GIT_COMMIT
516                 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
517                         die "tag name filter failed: $filter_tag_name"
518
519                 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
520
521                 if [ "$type" = "tag" ]; then
522                         new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
523                                                 "$new_sha1" "$new_ref"
524                                 git cat-file tag "$ref" |
525                                 sed -n \
526                                     -e '1,/^$/{
527                                           /^object /d
528                                           /^type /d
529                                           /^tag /d
530                                         }' \
531                                     -e '/^-----BEGIN PGP SIGNATURE-----/q' \
532                                     -e 'p' ) |
533                                 git mktag) ||
534                                 die "Could not create new tag object for $ref"
535                         if git cat-file tag "$ref" | \
536                            sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
537                         then
538                                 warn "gpg signature stripped from tag object $sha1t"
539                         fi
540                 fi
541
542                 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
543                         die "Could not write tag $new_ref"
544         done
545 fi
546
547 cd "$orig_dir"
548 rm -rf "$tempdir"
549
550 trap - 0
551
552 unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
553 test -z "$ORIG_GIT_DIR" || {
554         GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
555 }
556 test -z "$ORIG_GIT_WORK_TREE" || {
557         GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
558         export GIT_WORK_TREE
559 }
560 test -z "$ORIG_GIT_INDEX_FILE" || {
561         GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
562         export GIT_INDEX_FILE
563 }
564
565 if [ "$(is_bare_repository)" = false ]; then
566         git read-tree -u -m HEAD || exit
567 fi
568
569 exit 0