#!/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.
# The following functions will also be available in the commit filter:
functions=$(cat << \EOF
EMPTY_TREE=$(git hash-object -t tree /dev/null)
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 "$1";
shift;
done;
}
# if you run 'git_commit_non_empty_tree "$@"' in a commit filter,
# it will skip commits that leave the tree untouched, commit the other.
git_commit_non_empty_tree()
{
if test $# = 3 && test "$1" = $(git rev-parse "$3^{tree}"); then
map "$3"
elif test $# = 1 && test "$1" = $EMPTY_TREE; then
:
else
git commit-tree "$@"
fi
}
# override die(): this version puts in an extra line break, so that
# the progress is still visible
die()
{
echo >&2
echo "$*" >&2
exit 1
}
EOF
)
eval "$functions"
finish_ident() {
# Ensure non-empty id name.
echo "case \"\$GIT_$1_NAME\" in \"\") GIT_$1_NAME=\"\${GIT_$1_EMAIL%%@*}\" && export GIT_$1_NAME;; esac"
# And make sure everything is exported.
echo "export GIT_$1_NAME"
echo "export GIT_$1_EMAIL"
echo "export GIT_$1_DATE"
}
set_ident () {
parse_ident_from_commit author AUTHOR committer COMMITTER
finish_ident AUTHOR
finish_ident COMMITTER
}
USAGE="[--setup <command>] [--subdirectory-filter <directory>] [--env-filter <command>]
[--tree-filter <command>] [--index-filter <command>]
[--parent-filter <command>] [--msg-filter <command>]
[--commit-filter <command>] [--tag-name-filter <command>]
[--original <namespace>]
[-d <directory>] [-f | --force] [--state-branch <branch>]
[--] [<rev-list options>...]"
OPTIONS_SPEC=
. git-sh-setup
if [ "$(is_bare_repository)" = false ]; then
require_clean_work_tree 'rewrite branches'
fi
tempdir=.git-rewrite
filter_setup=
filter_env=
filter_tree=
filter_index=
filter_parent=
filter_msg=cat
filter_commit=
filter_tag_name=
filter_subdir=
state_branch=
orig_namespace=refs/original/
force=
prune_empty=
remap_to_ancestor=
while :
do
case "$1" in
--)
shift
break
;;
--force|-f)
shift
force=t
continue
;;
--remap-to-ancestor)
# deprecated ($remap_to_ancestor is set now automatically)
shift
remap_to_ancestor=t
continue
;;
--prune-empty)
shift
prune_empty=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="$OPTARG"
;;
--setup)
filter_setup="$OPTARG"
;;
--subdirectory-filter)
filter_subdir="$OPTARG"
remap_to_ancestor=t
;;
--env-filter)
filter_env="$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="$functions; $OPTARG"
;;
--tag-name-filter)
filter_tag_name="$OPTARG"
;;
--original)
orig_namespace=$(expr "$OPTARG/" : '\(.*[^/]\)/*$')/
;;
--state-branch)
state_branch="$OPTARG"
;;
*)
usage
;;
esac
done
case "$prune_empty,$filter_commit" in
,)
filter_commit='git commit-tree "$@"';;
t,)
filter_commit="$functions;"' git_commit_non_empty_tree "$@"';;
,*)
;;
*)
die "Cannot set --prune-empty and --commit-filter at the same time"
esac
case "$force" in
t)
rm -rf "$tempdir"
;;
'')
test -d "$tempdir" &&
die "$tempdir already exists, please remove it"
esac
orig_dir=$(pwd)
mkdir -p "$tempdir/t" &&
tempdir="$(cd "$tempdir"; pwd)" &&
cd "$tempdir/t" &&
workdir="$(pwd)" ||
die ""
# Remove tempdir on exit
trap 'cd "$orig_dir"; rm -rf "$tempdir"' 0
ORIG_GIT_DIR="$GIT_DIR"
ORIG_GIT_WORK_TREE="$GIT_WORK_TREE"
ORIG_GIT_INDEX_FILE="$GIT_INDEX_FILE"
ORIG_GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME"
ORIG_GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL"
ORIG_GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE"
ORIG_GIT_COMMITTER_NAME="$GIT_COMMITTER_NAME"
ORIG_GIT_COMMITTER_EMAIL="$GIT_COMMITTER_EMAIL"
ORIG_GIT_COMMITTER_DATE="$GIT_COMMITTER_DATE"
GIT_WORK_TREE=.
export GIT_DIR GIT_WORK_TREE
# Make sure refs/original is empty
git for-each-ref > "$tempdir"/backup-refs || exit
while read sha1 type name
do
case "$force,$name" in
,$orig_namespace*)
die "Cannot create a new backup.
A previous backup already exists in $orig_namespace
Force overwriting the backup with -f"
;;
t,$orig_namespace*)
git update-ref -d "$name" $sha1
;;
esac
done < "$tempdir"/backup-refs
# The refs should be updated if their heads were rewritten
git rev-parse --no-flags --revs-only --symbolic-full-name \
--default HEAD "$@" > "$tempdir"/raw-refs || exit
while read ref
do
case "$ref" in ^?*) continue ;; esac
if git rev-parse --verify "$ref"^0 >/dev/null 2>&1
then
echo "$ref"
else
warn "WARNING: not rewriting '$ref' (not a committish)"
fi
done >"$tempdir"/heads <"$tempdir"/raw-refs
test -s "$tempdir"/heads ||
die "You must specify a ref to rewrite."
GIT_INDEX_FILE="$(pwd)/../index"
export GIT_INDEX_FILE
# map old->new commit ids for rewriting parents
mkdir ../map || die "Could not create map/ directory"
if test -n "$state_branch"
then
state_commit=$(git rev-parse --no-flags --revs-only "$state_branch")
if test -n "$state_commit"
then
echo "Populating map from $state_branch ($state_commit)" 1>&2
perl -e'open(MAP, "-|", "git show $ARGV[0]:filter.map") or die;
while (<MAP>) {
m/(.*):(.*)/ or die;
open F, ">../map/$1" or die;
print F "$2" or die;
close(F) or die;
}
close(MAP) or die;' "$state_commit" \
|| die "Unable to load state from $state_branch:filter.map"
else
echo "Branch $state_branch does not exist. Will create" 1>&2
fi
fi
# we need "--" only if there are no path arguments in $@
nonrevs=$(git rev-parse --no-revs "$@") || exit
if test -z "$nonrevs"
then
dashdash=--
else
dashdash=
remap_to_ancestor=t
fi
git rev-parse --revs-only "$@" >../parse
case "$filter_subdir" in
"")
eval set -- "$(git rev-parse --sq --no-revs "$@")"
;;
*)
eval set -- "$(git rev-parse --sq --no-revs "$@" $dashdash \
"$filter_subdir")"
;;
esac
git rev-list --reverse --topo-order --default HEAD \
--parents --simplify-merges --stdin "$@" <../parse >../revs ||
die "Could not get the commits"
commits=$(wc -l <../revs | tr -d " ")
test $commits -eq 0 && die_with_status 2 "Found nothing to rewrite"
# Rewrite the commits
report_progress ()
{
if test -n "$progress" &&
test $git_filter_branch__commit_count -gt $next_sample_at
then
count=$git_filter_branch__commit_count
now=$(date +%s)
elapsed=$(($now - $start_timestamp))
remaining=$(( ($commits - $count) * $elapsed / $count ))
if test $elapsed -gt 0
then
next_sample_at=$(( ($elapsed + 1) * $count / $elapsed ))
else
next_sample_at=$(($next_sample_at + 1))
fi
progress=" ($elapsed seconds passed, remaining $remaining predicted)"
fi
printf "\rRewrite $commit ($count/$commits)$progress "
}
git_filter_branch__commit_count=0
progress= start_timestamp=
if date '+%s' 2>/dev/null | grep -q '^[0-9][0-9]*$'
then
next_sample_at=0
progress="dummy to ensure this is not empty"
start_timestamp=$(date '+%s')
fi
if test -n "$filter_index" ||
test -n "$filter_tree" ||
test -n "$filter_subdir"
then
need_index=t
else
need_index=
fi
eval "$filter_setup" < /dev/null ||
die "filter setup failed: $filter_setup"
while read commit parents; do
git_filter_branch__commit_count=$(($git_filter_branch__commit_count+1))
report_progress
test -f "$workdir"/../map/$commit && continue
case "$filter_subdir" in
"")
if test -n "$need_index"
then
GIT_ALLOW_NULL_SHA1=1 git read-tree -i -m $commit
fi
;;
*)
# The commit may not have the subdirectory at all
err=$(GIT_ALLOW_NULL_SHA1=1 \
git read-tree -i -m $commit:"$filter_subdir" 2>&1) || {
if ! git rev-parse -q --verify $commit:"$filter_subdir"
then
rm -f "$GIT_INDEX_FILE"
else
echo >&2 "$err"
false
fi
}
esac || die "Could not initialize the index"
GIT_COMMIT=$commit
export GIT_COMMIT
git cat-file commit "$commit" >../commit ||
die "Cannot read commit $commit"
eval "$(set_ident <../commit)" ||
die "setting author/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 $commit removed are now still in the working tree;
# remove them, else they would be added again
git clean -d -q -f -x
eval "$filter_tree" < /dev/null ||
die "tree filter failed: $filter_tree"
(
git diff-index -r --name-only --ignore-submodules $commit -- &&
git ls-files --others
) > "$tempdir"/tree-state || exit
git update-index --add --replace --remove --stdin \
< "$tempdir"/tree-state || exit
fi
eval "$filter_index" < /dev/null ||
die "index filter failed: $filter_index"
parentstr=
for parent in $parents; do
for reparent in $(map "$parent"); do
case "$parentstr " in
*" -p $reparent "*)
;;
*)
parentstr="$parentstr -p $reparent"
;;
esac
done
done
if [ "$filter_parent" ]; then
parentstr="$(echo "$parentstr" | eval "$filter_parent")" ||
die "parent filter failed: $filter_parent"
fi
{
while IFS='' read -r header_line && test -n "$header_line"
do
# skip header lines...
:;
done
# and output the actual commit message
cat
} <../commit |
eval "$filter_msg" > ../message ||
die "msg filter failed: $filter_msg"
if test -n "$need_index"
then
tree=$(git write-tree)
else
tree=$(git rev-parse "$commit^{tree}")
fi
workdir=$workdir @SHELL_PATH@ -c "$filter_commit" "git commit-tree" \
"$tree" $parentstr < ../message > ../map/$commit ||
die "could not write rewritten commit"
done <../revs
# If we are filtering for paths, as in the 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.
# Ancestor remapping fixes this by mapping these heads to the unique
# nearest ancestor that survived the pruning.
if test "$remap_to_ancestor" = t
then
while read ref
do
sha1=$(git rev-parse "$ref"^0)
test -f "$workdir"/../map/$sha1 && continue
ancestor=$(git rev-list --simplify-merges -1 "$ref" "$@")
test "$ancestor" && echo $(map $ancestor) >> "$workdir"/../map/$sha1
done < "$tempdir"/heads
fi
# 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"
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"
if ! git update-ref -m "filter-branch: rewrite" \
"$ref" $rewritten $sha1 2>/dev/null; then
if test $(git cat-file -t "$ref") = tag; then
if test -z "$filter_tag_name"; then
warn "WARNING: You said to rewrite tagged commits, but not the corresponding tag."
warn "WARNING: Perhaps use '--tag-name-filter cat' to rewrite the tag."
fi
else
die "Could not rewrite $ref"
fi
fi
;;
*)
# NEEDSWORK: possibly add -Werror, making this an error
warn "WARNING: '$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" $sha1 ||
exit
done < "$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="$(git rev-parse -q "$sha1"^{commit})" || continue
fi
[ -f "../map/$sha1" ] || continue
new_sha1="$(cat "../map/$sha1")"
GIT_COMMIT="$sha1"
export GIT_COMMIT
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
new_sha1=$( ( printf 'object %s\ntype commit\ntag %s\n' \
"$new_sha1" "$new_ref"
git cat-file tag "$ref" |
sed -n \
-e '1,/^$/{
/^object /d
/^type /d
/^tag /d
}' \
-e '/^-----BEGIN PGP SIGNATURE-----/q' \
-e 'p' ) |
git hash-object -t tag -w --stdin) ||
die "Could not create new tag object for $ref"
if git cat-file tag "$ref" | \
sane_grep '^-----BEGIN PGP SIGNATURE-----' >/dev/null 2>&1
then
warn "gpg signature stripped from tag object $sha1t"
fi
fi
git update-ref "refs/tags/$new_ref" "$new_sha1" ||
die "Could not write tag $new_ref"
done
fi
unset GIT_DIR GIT_WORK_TREE GIT_INDEX_FILE
unset GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_AUTHOR_DATE
unset GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL GIT_COMMITTER_DATE
test -z "$ORIG_GIT_DIR" || {
GIT_DIR="$ORIG_GIT_DIR" && export GIT_DIR
}
test -z "$ORIG_GIT_WORK_TREE" || {
GIT_WORK_TREE="$ORIG_GIT_WORK_TREE" &&
export GIT_WORK_TREE
}
test -z "$ORIG_GIT_INDEX_FILE" || {
GIT_INDEX_FILE="$ORIG_GIT_INDEX_FILE" &&
export GIT_INDEX_FILE
}
test -z "$ORIG_GIT_AUTHOR_NAME" || {
GIT_AUTHOR_NAME="$ORIG_GIT_AUTHOR_NAME" &&
export GIT_AUTHOR_NAME
}
test -z "$ORIG_GIT_AUTHOR_EMAIL" || {
GIT_AUTHOR_EMAIL="$ORIG_GIT_AUTHOR_EMAIL" &&
export GIT_AUTHOR_EMAIL
}
test -z "$ORIG_GIT_AUTHOR_DATE" || {
GIT_AUTHOR_DATE="$ORIG_GIT_AUTHOR_DATE" &&
export GIT_AUTHOR_DATE
}
test -z "$ORIG_GIT_COMMITTER_NAME" || {
GIT_COMMITTER_NAME="$ORIG_GIT_COMMITTER_NAME" &&
export GIT_COMMITTER_NAME
}
test -z "$ORIG_GIT_COMMITTER_EMAIL" || {
GIT_COMMITTER_EMAIL="$ORIG_GIT_COMMITTER_EMAIL" &&
export GIT_COMMITTER_EMAIL
}
test -z "$ORIG_GIT_COMMITTER_DATE" || {
GIT_COMMITTER_DATE="$ORIG_GIT_COMMITTER_DATE" &&
export GIT_COMMITTER_DATE
}
if test -n "$state_branch"
then
echo "Saving rewrite state to $state_branch" 1>&2
state_blob=$(
perl -e'opendir D, "../map" or die;
open H, "|-", "git hash-object -w --stdin" or die;
foreach (sort readdir(D)) {
next if m/^\.\.?$/;
open F, "<../map/$_" or die;
chomp($f = <F>);
print H "$_:$f\n" or die;
}
close(H) or die;' || die "Unable to save state")
state_tree=$(printf '100644 blob %s\tfilter.map\n' "$state_blob" | git mktree)
if test -n "$state_commit"
then
state_commit=$(echo "Sync" | git commit-tree "$state_tree" -p "$state_commit")
else
state_commit=$(echo "Sync" | git commit-tree "$state_tree" )
fi
git update-ref "$state_branch" "$state_commit"
fi
cd "$orig_dir"
rm -rf "$tempdir"
trap - 0
if [ "$(is_bare_repository)" = false ]; then
git read-tree -u -m HEAD || exit
fi
exit 0
