git-write-tree should not crash if prefix does not exist
[git/git-p4.git] / git-filter-branch.sh
blobb5fa44920d40d3144567509a6922a07bb87977ae
1 #!/bin/sh
3 # Rewrite revision history
4 # Copyright (c) Petr Baudis, 2006
5 # Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
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.
11 USAGE="git-filter-branch [-d TEMPDIR] [FILTERS] DESTBRANCH [REV-RANGE]"
12 . git-sh-setup
14 warn () {
15 echo "$*" >&2
18 map()
20 # if it was not rewritten, take the original
21 if test -r "$workdir/../map/$1"
22 then
23 cat "$workdir/../map/$1"
24 else
25 echo "$1"
29 # override die(): this version puts in an extra line break, so that
30 # the progress is still visible
32 die()
34 echo >&2
35 echo "$*" >&2
36 exit 1
39 # When piped a commit, output a script to set the ident of either
40 # "author" or "committer
42 set_ident () {
43 lid="$(echo "$1" | tr "A-Z" "a-z")"
44 uid="$(echo "$1" | tr "a-z" "A-Z")"
45 pick_id_script='
46 /^'$lid' /{
47 s/'\''/'\''\\'\'\''/g
49 s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
50 s/'\''/'\''\'\'\''/g
51 s/.*/export GIT_'$uid'_NAME='\''&'\''/p
54 s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
55 s/'\''/'\''\'\'\''/g
56 s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
59 s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
60 s/'\''/'\''\'\'\''/g
61 s/.*/export GIT_'$uid'_DATE='\''&'\''/p
67 LANG=C LC_ALL=C sed -ne "$pick_id_script"
68 # Ensure non-empty id name.
69 echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
72 tempdir=.git-rewrite
73 filter_env=
74 filter_tree=
75 filter_index=
76 filter_parent=
77 filter_msg=cat
78 filter_commit='git commit-tree "$@"'
79 filter_tag_name=
80 filter_subdir=
81 orig_namespace=refs/original/
82 force=
83 while case "$#" in 0) usage;; esac
85 case "$1" in
86 --)
87 shift
88 break
90 --force|-f)
91 shift
92 force=t
93 continue
95 -*)
98 break;
99 esac
101 # all switches take one argument
102 ARG="$1"
103 case "$#" in 1) usage ;; esac
104 shift
105 OPTARG="$1"
106 shift
108 case "$ARG" in
110 tempdir="$OPTARG"
112 --env-filter)
113 filter_env="$OPTARG"
115 --tree-filter)
116 filter_tree="$OPTARG"
118 --index-filter)
119 filter_index="$OPTARG"
121 --parent-filter)
122 filter_parent="$OPTARG"
124 --msg-filter)
125 filter_msg="$OPTARG"
127 --commit-filter)
128 filter_commit="$OPTARG"
130 --tag-name-filter)
131 filter_tag_name="$OPTARG"
133 --subdirectory-filter)
134 filter_subdir="$OPTARG"
136 --original)
137 orig_namespace="$OPTARG"
140 usage
142 esac
143 done
145 case "$force" in
147 rm -rf "$tempdir"
150 test -d "$tempdir" &&
151 die "$tempdir already exists, please remove it"
152 esac
153 mkdir -p "$tempdir/t" &&
154 tempdir="$(cd "$tempdir"; pwd)" &&
155 cd "$tempdir/t" &&
156 workdir="$(pwd)" ||
157 die ""
159 # Make sure refs/original is empty
160 git for-each-ref > "$tempdir"/backup-refs
161 while read sha1 type name
163 case "$force,$name" in
164 ,$orig_namespace*)
165 die "Namespace $orig_namespace not empty"
167 t,$orig_namespace*)
168 git update-ref -d "$name" $sha1
170 esac
171 done < "$tempdir"/backup-refs
173 case "$GIT_DIR" in
177 GIT_DIR="$(pwd)/../../$GIT_DIR"
179 esac
180 export GIT_DIR GIT_WORK_TREE=.
182 # These refs should be updated if their heads were rewritten
184 git rev-parse --revs-only --symbolic "$@" |
185 while read ref
187 # normalize ref
188 case "$ref" in
189 HEAD)
190 ref="$(git symbolic-ref "$ref")"
192 refs/*)
195 ref="$(git for-each-ref --format='%(refname)' |
196 grep /"$ref")"
197 esac
199 git check-ref-format "$ref" && echo "$ref"
200 done > "$tempdir"/heads
202 test -s "$tempdir"/heads ||
203 die "Which ref do you want to rewrite?"
205 export GIT_INDEX_FILE="$(pwd)/../index"
206 git read-tree || die "Could not seed the index"
208 ret=0
210 # map old->new commit ids for rewriting parents
211 mkdir ../map || die "Could not create map/ directory"
213 case "$filter_subdir" in
215 git rev-list --reverse --topo-order --default HEAD \
216 --parents "$@"
219 git rev-list --reverse --topo-order --default HEAD \
220 --parents --full-history "$@" -- "$filter_subdir"
221 esac > ../revs || die "Could not get the commits"
222 commits=$(wc -l <../revs | tr -d " ")
224 test $commits -eq 0 && die "Found nothing to rewrite"
226 # Rewrite the commits
229 while read commit parents; do
230 i=$(($i+1))
231 printf "\rRewrite $commit ($i/$commits)"
233 case "$filter_subdir" in
235 git read-tree -i -m $commit
238 git read-tree -i -m $commit:"$filter_subdir"
239 esac || die "Could not initialize the index"
241 export GIT_COMMIT=$commit
242 git cat-file commit "$commit" >../commit ||
243 die "Cannot read commit $commit"
245 eval "$(set_ident AUTHOR <../commit)" ||
246 die "setting author failed for commit $commit"
247 eval "$(set_ident COMMITTER <../commit)" ||
248 die "setting committer failed for commit $commit"
249 eval "$filter_env" < /dev/null ||
250 die "env filter failed: $filter_env"
252 if [ "$filter_tree" ]; then
253 git checkout-index -f -u -a ||
254 die "Could not checkout the index"
255 # files that $commit removed are now still in the working tree;
256 # remove them, else they would be added again
257 git ls-files -z --others | xargs -0 rm -f
258 eval "$filter_tree" < /dev/null ||
259 die "tree filter failed: $filter_tree"
261 git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
262 xargs -0 git update-index --add --replace --remove
263 git ls-files -z --others | \
264 xargs -0 git update-index --add --replace --remove
267 eval "$filter_index" < /dev/null ||
268 die "index filter failed: $filter_index"
270 parentstr=
271 for parent in $parents; do
272 for reparent in $(map "$parent"); do
273 parentstr="$parentstr -p $reparent"
274 done
275 done
276 if [ "$filter_parent" ]; then
277 parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
278 die "parent filter failed: $filter_parent"
281 sed -e '1,/^$/d' <../commit | \
282 eval "$filter_msg" > ../message ||
283 die "msg filter failed: $filter_msg"
284 sh -c "$filter_commit" "git commit-tree" \
285 $(git write-tree) $parentstr < ../message > ../map/$commit
286 done <../revs
288 # In case of a subdirectory filter, it is possible that a specified head
289 # is not in the set of rewritten commits, because it was pruned by the
290 # revision walker. Fix it by mapping these heads to the next rewritten
291 # ancestor(s), i.e. the boundaries in the set of rewritten commits.
293 # NEEDSWORK: we should sort the unmapped refs topologically first
294 while read ref
296 sha1=$(git rev-parse "$ref"^0)
297 test -f "$workdir"/../map/$sha1 && continue
298 # Assign the boundarie(s) in the set of rewritten commits
299 # as the replacement commit(s).
300 # (This would look a bit nicer if --not --stdin worked.)
301 for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
302 git rev-list $ref --boundary --stdin |
303 sed -n "s/^-//p")
305 map $p >> "$workdir"/../map/$sha1
306 done
307 done < "$tempdir"/heads
309 # Finally update the refs
311 _x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
312 _x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
313 count=0
314 echo
315 while read ref
317 # avoid rewriting a ref twice
318 test -f "$orig_namespace$ref" && continue
320 sha1=$(git rev-parse "$ref"^0)
321 rewritten=$(map $sha1)
323 test $sha1 = "$rewritten" &&
324 warn "WARNING: Ref '$ref' is unchanged" &&
325 continue
327 case "$rewritten" in
329 echo "Ref '$ref' was deleted"
330 git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
331 die "Could not delete $ref"
333 $_x40)
334 echo "Ref '$ref' was rewritten"
335 git update-ref -m "filter-branch: rewrite" \
336 "$ref" $rewritten $sha1 ||
337 die "Could not rewrite $ref"
340 # NEEDSWORK: possibly add -Werror, making this an error
341 warn "WARNING: '$ref' was rewritten into multiple commits:"
342 warn "$rewritten"
343 warn "WARNING: Ref '$ref' points to the first one now."
344 rewritten=$(echo "$rewritten" | head -n 1)
345 git update-ref -m "filter-branch: rewrite to first" \
346 "$ref" $rewritten $sha1 ||
347 die "Could not rewrite $ref"
349 esac
350 git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
351 count=$(($count+1))
352 done < "$tempdir"/heads
354 # TODO: This should possibly go, with the semantics that all positive given
355 # refs are updated, and their original heads stored in refs/original/
356 # Filter tags
358 if [ "$filter_tag_name" ]; then
359 git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
360 while read sha1 type ref; do
361 ref="${ref#refs/tags/}"
362 # XXX: Rewrite tagged trees as well?
363 if [ "$type" != "commit" -a "$type" != "tag" ]; then
364 continue;
367 if [ "$type" = "tag" ]; then
368 # Dereference to a commit
369 sha1t="$sha1"
370 sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
373 [ -f "../map/$sha1" ] || continue
374 new_sha1="$(cat "../map/$sha1")"
375 export GIT_COMMIT="$sha1"
376 new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
377 die "tag name filter failed: $filter_tag_name"
379 echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
381 if [ "$type" = "tag" ]; then
382 # Warn that we are not rewriting the tag object itself.
383 warn "unreferencing tag object $sha1t"
386 git update-ref "refs/tags/$new_ref" "$new_sha1" ||
387 die "Could not write tag $new_ref"
388 done
391 cd ../..
392 rm -rf "$tempdir"
393 echo
394 test $count -gt 0 && echo "These refs were rewritten:"
395 git show-ref | grep ^"$orig_namespace"
397 exit $ret