# a new branch. You can specify a number of filters to modify the commits,
# files and trees.
-set -e
-
USAGE="git-filter-branch [-d TEMPDIR] [FILTERS] DESTBRANCH [REV-RANGE]"
. git-sh-setup
filter_commit='git commit-tree "$@"'
filter_tag_name=
filter_subdir=
+orig_namespace=refs/original/
+force=
while case "$#" in 0) usage;; esac
do
case "$1" in
shift
break
;;
+ --force|-f)
+ shift
+ force=t
+ continue
+ ;;
-*)
;;
*)
--subdirectory-filter)
filter_subdir="$OPTARG"
;;
+ --original)
+ orig_namespace="$OPTARG"
+ ;;
*)
usage
;;
esac
done
-dstbranch="$1"
-shift
-test -n "$dstbranch" || die "missing branch name"
-git show-ref "refs/heads/$dstbranch" 2> /dev/null &&
- die "branch $dstbranch already exists"
-
-test ! -e "$tempdir" || die "$tempdir already exists, please remove it"
-mkdir -p "$tempdir/t"
-cd "$tempdir/t"
-workdir="$(pwd)"
+case "$force" in
+t)
+ rm -rf "$tempdir"
+;;
+'')
+ test -d "$tempdir" &&
+ die "$tempdir already exists, please remove it"
+esac
+mkdir -p "$tempdir/t" &&
+tempdir="$(cd "$tempdir"; pwd)" &&
+cd "$tempdir/t" &&
+workdir="$(pwd)" ||
+die ""
+
+# Make sure refs/original is empty
+git for-each-ref > "$tempdir"/backup-refs
+while read sha1 type name
+do
+ case "$force,$name" in
+ ,$orig_namespace*)
+ die "Namespace $orig_namespace not empty"
+ ;;
+ t,$orig_namespace*)
+ git update-ref -d "$name" $sha1
+ ;;
+ esac
+done < "$tempdir"/backup-refs
case "$GIT_DIR" in
/*)
esac
export GIT_DIR GIT_WORK_TREE=.
+# These refs should be updated if their heads were rewritten
+
+git rev-parse --revs-only --symbolic "$@" |
+while read ref
+do
+ # normalize ref
+ case "$ref" in
+ HEAD)
+ ref="$(git symbolic-ref "$ref")"
+ ;;
+ refs/*)
+ ;;
+ *)
+ ref="$(git for-each-ref --format='%(refname)' |
+ grep /"$ref")"
+ esac
+
+ git check-ref-format "$ref" && echo "$ref"
+done > "$tempdir"/heads
+
+test -s "$tempdir"/heads ||
+ die "Which ref do you want to rewrite?"
+
export GIT_INDEX_FILE="$(pwd)/../index"
-git read-tree # seed the index file
+git read-tree || die "Could not seed the index"
ret=0
-
-mkdir ../map # map old->new commit ids for rewriting parents
+# map old->new commit ids for rewriting parents
+mkdir ../map || die "Could not create map/ directory"
case "$filter_subdir" in
"")
*)
git rev-list --reverse --topo-order --default HEAD \
--parents --full-history "$@" -- "$filter_subdir"
-esac > ../revs
+esac > ../revs || die "Could not get the commits"
commits=$(wc -l <../revs | tr -d " ")
test $commits -eq 0 && die "Found nothing to rewrite"
+# Rewrite the commits
+
i=0
while read commit parents; do
i=$(($i+1))
;;
*)
git read-tree -i -m $commit:"$filter_subdir"
- esac
+ esac || die "Could not initialize the index"
export GIT_COMMIT=$commit
- git cat-file commit "$commit" >../commit
+ git cat-file commit "$commit" >../commit ||
+ die "Cannot read commit $commit"
eval "$(set_ident AUTHOR <../commit)" ||
die "setting author failed for commit $commit"
die "env filter failed: $filter_env"
if [ "$filter_tree" ]; then
- git checkout-index -f -u -a
+ git checkout-index -f -u -a ||
+ die "Could not checkout the index"
# files that $commit removed are now still in the working tree;
# remove them, else they would be added again
git ls-files -z --others | xargs -0 rm -f
$(git write-tree) $parentstr < ../message > ../map/$commit
done <../revs
-src_head=$(tail -n 1 ../revs | sed -e 's/ .*//')
-target_head=$(head -n 1 ../map/$src_head)
-case "$target_head" in
-'')
- echo Nothing rewritten
+# In case of a subdirectory filter, it is possible that a specified head
+# is not in the set of rewritten commits, because it was pruned by the
+# revision walker. Fix it by mapping these heads to the next rewritten
+# ancestor(s), i.e. the boundaries in the set of rewritten commits.
+
+# NEEDSWORK: we should sort the unmapped refs topologically first
+while read ref
+do
+ sha1=$(git rev-parse "$ref"^0)
+ test -f "$workdir"/../map/$sha1 && continue
+ # Assign the boundarie(s) in the set of rewritten commits
+ # as the replacement commit(s).
+ # (This would look a bit nicer if --not --stdin worked.)
+ for p in $( (cd "$workdir"/../map; ls | sed "s/^/^/") |
+ git rev-list $ref --boundary --stdin |
+ sed -n "s/^-//p")
+ do
+ map $p >> "$workdir"/../map/$sha1
+ done
+done < "$tempdir"/heads
+
+# Finally update the refs
+
+_x40='[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f]'
+_x40="$_x40$_x40$_x40$_x40$_x40$_x40$_x40$_x40"
+count=0
+echo
+while read ref
+do
+ # avoid rewriting a ref twice
+ test -f "$orig_namespace$ref" && continue
+
+ sha1=$(git rev-parse "$ref"^0)
+ rewritten=$(map $sha1)
+
+ test $sha1 = "$rewritten" &&
+ warn "WARNING: Ref '$ref' is unchanged" &&
+ continue
+
+ case "$rewritten" in
+ '')
+ echo "Ref '$ref' was deleted"
+ git update-ref -m "filter-branch: delete" -d "$ref" $sha1 ||
+ die "Could not delete $ref"
;;
-*)
- git update-ref refs/heads/"$dstbranch" $target_head
- if [ $(wc -l <../map/$src_head) -gt 1 ]; then
- echo "WARNING: Your commit filter caused the head commit to expand to several rewritten commits. Only the first such commit was recorded as the current $dstbranch head but you will need to resolve the situation now (probably by manually merging the other commits). These are all the commits:" >&2
- sed 's/^/ /' ../map/$src_head >&2
- ret=1
- fi
+ $_x40)
+ echo "Ref '$ref' was rewritten"
+ git update-ref -m "filter-branch: rewrite" \
+ "$ref" $rewritten $sha1 ||
+ die "Could not rewrite $ref"
;;
-esac
+ *)
+ # NEEDSWORK: possibly add -Werror, making this an error
+ warn "WARNING: '$ref' was rewritten into multiple commits:"
+ warn "$rewritten"
+ warn "WARNING: Ref '$ref' points to the first one now."
+ rewritten=$(echo "$rewritten" | head -n 1)
+ git update-ref -m "filter-branch: rewrite to first" \
+ "$ref" $rewritten $sha1 ||
+ die "Could not rewrite $ref"
+ ;;
+ esac
+ git update-ref -m "filter-branch: backup" "$orig_namespace$ref" $sha1
+ count=$(($count+1))
+done < "$tempdir"/heads
+
+# TODO: This should possibly go, with the semantics that all positive given
+# refs are updated, and their original heads stored in refs/original/
+# Filter tags
if [ "$filter_tag_name" ]; then
git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
warn "unreferencing tag object $sha1t"
fi
- git update-ref "refs/tags/$new_ref" "$new_sha1"
+ git update-ref "refs/tags/$new_ref" "$new_sha1" ||
+ die "Could not write tag $new_ref"
done
fi
cd ../..
rm -rf "$tempdir"
-printf "\nRewritten history saved to the $dstbranch branch\n"
+echo
+test $count -gt 0 && echo "These refs were rewritten:"
+git show-ref | grep ^"$orig_namespace"
exit $ret