git/git-filter-branch.sh
Johannes Schindelin f95eef15f2 filter-branch: introduce convenience function "skip_commit"
With this function, a commit filter can leave out unwanted commits
(such as temporary commits).  It does _not_ undo the changeset
corresponding to that commit, but it _skips_ the revision.  IOW
no tree object is changed by this.

If you like to commit early and often, but want to filter out all
intermediate commits, marked by "@@@" in the commit message, you can
now do this with

	git filter-branch --commit-filter '
		if git cat-file commit $GIT_COMMIT | grep '@@@' > /dev/null;
		then
			skip_commit "$@";
		else
			git commit-tree "$@";
		fi' newbranch

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-31 23:22:51 -07:00

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#!/bin/sh
#
# Rewrite revision history
# Copyright (c) Petr Baudis, 2006
# Minimal changes to "port" it to core-git (c) Johannes Schindelin, 2007
#
# Lets you rewrite the revision history of the current branch, creating
# a new branch. You can specify a number of filters to modify the commits,
# files and trees.
warn () {
echo "$*" >&2
}
map()
{
# if it was not rewritten, take the original
if test -r "$workdir/../map/$1"
then
cat "$workdir/../map/$1"
else
echo "$1"
fi
}
# if you run 'skip_commit "$@"' in a commit filter, it will print
# the (mapped) parents, effectively skipping the commit.
skip_commit()
{
shift;
while [ -n "$1" ];
do
shift;
map "$1";
shift;
done;
}
# override die(): this version puts in an extra line break, so that
# the progress is still visible
die()
{
echo >&2
echo "$*" >&2
exit 1
}
# When piped a commit, output a script to set the ident of either
# "author" or "committer
set_ident () {
lid="$(echo "$1" | tr "A-Z" "a-z")"
uid="$(echo "$1" | tr "a-z" "A-Z")"
pick_id_script='
/^'$lid' /{
s/'\''/'\''\\'\'\''/g
h
s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
s/'\''/'\''\'\'\''/g
s/.*/export GIT_'$uid'_NAME='\''&'\''/p
g
s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
s/'\''/'\''\'\'\''/g
s/.*/export GIT_'$uid'_EMAIL='\''&'\''/p
g
s/^'$lid' [^<]* <[^>]*> \(.*\)$/\1/
s/'\''/'\''\'\'\''/g
s/.*/export GIT_'$uid'_DATE='\''&'\''/p
q
}
'
LANG=C LC_ALL=C sed -ne "$pick_id_script"
# Ensure non-empty id name.
echo "[ -n \"\$GIT_${uid}_NAME\" ] || export GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\""
}
# This script can be sourced by the commit filter to get the functions
test "a$SOURCE_FUNCTIONS" = a1 && return
this_script="$(cd "$(dirname "$0")"; pwd)"/$(basename "$0")
export this_script
USAGE="[--env-filter <command>] [--tree-filter <command>] \
[--index-filter <command>] [--parent-filter <command>] \
[--msg-filter <command>] [--commit-filter <command>] \
[--tag-name-filter <command>] [--subdirectory-filter <directory>] \
[--original <namespace>] [-d <directory>] [-f | --force] \
[<rev-list options>...]"
. git-sh-setup
tempdir=.git-rewrite
filter_env=
filter_tree=
filter_index=
filter_parent=
filter_msg=cat
filter_commit='git commit-tree "$@"'
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
;;
-*)
;;
*)
break;
esac
# all switches take one argument
ARG="$1"
case "$#" in 1) usage ;; esac
shift
OPTARG="$1"
shift
case "$ARG" in
-d)
tempdir="$OPTARG"
;;
--env-filter)
filter_env="$OPTARG"
;;
--tree-filter)
filter_tree="$OPTARG"
;;
--index-filter)
filter_index="$OPTARG"
;;
--parent-filter)
filter_parent="$OPTARG"
;;
--msg-filter)
filter_msg="$OPTARG"
;;
--commit-filter)
filter_commit='SOURCE_FUNCTIONS=1 . "$this_script";'" $OPTARG"
;;
--tag-name-filter)
filter_tag_name="$OPTARG"
;;
--subdirectory-filter)
filter_subdir="$OPTARG"
;;
--original)
orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
;;
*)
usage
;;
esac
done
case "$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
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="$(pwd)/../index"
git read-tree || die "Could not seed the index"
ret=0
# map old->new commit ids for rewriting parents
mkdir ../map || die "Could not create map/ directory"
case "$filter_subdir" in
"")
git rev-list --reverse --topo-order --default HEAD \
--parents "$@"
;;
*)
git rev-list --reverse --topo-order --default HEAD \
--parents --full-history "$@" -- "$filter_subdir"
esac > ../revs || die "Could not get the commits"
commits=$(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))
printf "\rRewrite $commit ($i/$commits)"
case "$filter_subdir" in
"")
git read-tree -i -m $commit
;;
*)
git read-tree -i -m $commit:"$filter_subdir"
esac || die "Could not initialize the index"
export GIT_COMMIT=$commit
git cat-file commit "$commit" >../commit ||
die "Cannot read commit $commit"
eval "$(set_ident AUTHOR <../commit)" ||
die "setting author failed for commit $commit"
eval "$(set_ident COMMITTER <../commit)" ||
die "setting committer failed for commit $commit"
eval "$filter_env" < /dev/null ||
die "env filter failed: $filter_env"
if [ "$filter_tree" ]; then
git checkout-index -f -u -a ||
die "Could not checkout the index"
# files that $commit removed are now still in the working tree;
# remove them, else they would be added again
git ls-files -z --others | xargs -0 rm -f
eval "$filter_tree" < /dev/null ||
die "tree filter failed: $filter_tree"
git diff-index -r $commit | cut -f 2- | tr '\n' '\0' | \
xargs -0 git update-index --add --replace --remove
git ls-files -z --others | \
xargs -0 git update-index --add --replace --remove
fi
eval "$filter_index" < /dev/null ||
die "index filter failed: $filter_index"
parentstr=
for parent in $parents; do
for reparent in $(map "$parent"); do
parentstr="$parentstr -p $reparent"
done
done
if [ "$filter_parent" ]; then
parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
die "parent filter failed: $filter_parent"
fi
sed -e '1,/^$/d' <../commit | \
eval "$filter_msg" > ../message ||
die "msg filter failed: $filter_msg"
sh -c "$filter_commit" "git commit-tree" \
$(git write-tree) $parentstr < ../message > ../map/$commit
done <../revs
# 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"
;;
$_x40)
echo "Ref '$ref' was rewritten"
git update-ref -m "filter-branch: rewrite" \
"$ref" $rewritten $sha1 ||
die "Could not rewrite $ref"
;;
*)
# NEEDSWORK: possibly add -Werror, making this an error
warn "WARNING: '$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 [ "$filter_tag_name" ]; then
git for-each-ref --format='%(objectname) %(objecttype) %(refname)' refs/tags |
while read sha1 type ref; do
ref="${ref#refs/tags/}"
# XXX: Rewrite tagged trees as well?
if [ "$type" != "commit" -a "$type" != "tag" ]; then
continue;
fi
if [ "$type" = "tag" ]; then
# Dereference to a commit
sha1t="$sha1"
sha1="$(git rev-parse "$sha1"^{commit} 2>/dev/null)" || continue
fi
[ -f "../map/$sha1" ] || continue
new_sha1="$(cat "../map/$sha1")"
export GIT_COMMIT="$sha1"
new_ref="$(echo "$ref" | eval "$filter_tag_name")" ||
die "tag name filter failed: $filter_tag_name"
echo "$ref -> $new_ref ($sha1 -> $new_sha1)"
if [ "$type" = "tag" ]; then
# Warn that we are not rewriting the tag object itself.
warn "unreferencing tag object $sha1t"
fi
git update-ref "refs/tags/$new_ref" "$new_sha1" ||
die "Could not write tag $new_ref"
done
fi
cd ../..
rm -rf "$tempdir"
echo
test $count -gt 0 && echo "These refs were rewritten:"
git show-ref | grep ^"$orig_namespace"
exit $ret