#
# git-subtree.sh: split/join git repositories in subdirectories of this one
#
-# Copyright (
c) 2009 Avery Pennarun <apenwarr@gmail.com>
+# Copyright (
C) 2009 Avery Pennarun <apenwarr@gmail.com>
#
OPTS_SPEC="\
-git subtree split <revisions> -- <subdir>
+git subtree split [--rejoin] [--onto rev] <commit...> -- <path>
git subtree merge
git subtree does foo and bar!
h,help show the help
q quiet
v verbose
+onto= existing subtree revision to search for parent
+rejoin merge the new branch back into HEAD
"
eval $(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)
. git-sh-setup
quiet=
command=
+onto=
+rejoin=
debug()
{
shift
case "$opt" in
-q) quiet=1 ;;
+ --onto) onto="$1"; shift ;;
+ --rejoin) rejoin=1 ;;
--) break ;;
esac
done
rm -rf "$cachedir" || die "Can't delete old cachedir: $cachedir"
mkdir -p "$cachedir" || die "Can't create new cachedir: $cachedir"
debug "Using cachedir: $cachedir" >&2
- echo "$cachedir"
}
cache_get()
{
oldrev="$1"
newrev="$2"
- if [ -e "$cachedir/$oldrev" ]; then
+ if [ "$oldrev" != "latest_old" \
+ -a "$oldrev" != "latest_new" \
+ -a -e "$cachedir/$oldrev" ]; then
die "cache for $oldrev already exists!"
fi
echo "$newrev" >"$cachedir/$oldrev"
}
+find_existing_splits()
+{
+ debug "Looking for prior splits..."
+ dir="$1"
+ revs="$2"
+ git log --grep="^git-subtree-dir: $dir\$" \
+ --pretty=format:'%s%n%n%b%nEND' "$revs" |
+ while read a b junk; do
+ case "$a" in
+ git-subtree-mainline:) main="$b" ;;
+ git-subtree-split:) sub="$b" ;;
+ *)
+ if [ -n "$main" -a -n "$sub" ]; then
+ debug " Prior: $main -> $sub"
+ cache_set $main $sub
+ echo "^$main^ ^$sub^"
+ main=
+ sub=
+ fi
+ ;;
+ esac
+ done
+}
+
+copy_commit()
+{
+ # We're doing to set some environment vars here, so
+ # do it in a subshell to get rid of them safely later
+ git log -1 --pretty=format:'%an%n%ae%n%ad%n%cn%n%ce%n%cd%n%s%n%n%b' "$1" |
+ (
+ read GIT_AUTHOR_NAME
+ read GIT_AUTHOR_EMAIL
+ read GIT_AUTHOR_DATE
+ read GIT_COMMITTER_NAME
+ read GIT_COMMITTER_EMAIL
+ read GIT_COMMITTER_DATE
+ export GIT_AUTHOR_NAME \
+ GIT_AUTHOR_EMAIL \
+ GIT_AUTHOR_DATE \
+ GIT_COMMITTER_NAME \
+ GIT_COMMITTER_EMAIL \
+ GIT_COMMITTER_DATE
+ git commit-tree "$2" $3 # reads the rest of stdin
+ ) || die "Can't copy commit $1"
+}
+
+merge_msg()
+{
+ dir="$1"
+ latest_old="$2"
+ latest_new="$3"
+ cat <<-EOF
+ Split '$dir/' into commit '$latest_new'
+
+ git-subtree-dir: $dir
+ git-subtree-mainline: $latest_old
+ git-subtree-split: $latest_new
+ EOF
+}
+
cmd_split()
{
debug "Splitting $dir..."
cache_setup || exit $?
- git rev-list --reverse --parents $revs -- "$dir" |
+ if [ -n "$onto" ]; then
+ echo "Reading history for --onto=$onto..."
+ git rev-list $onto |
+ while read rev; do
+ # the 'onto' history is already just the subdir, so
+ # any parent we find there can be used verbatim
+ debug " cache: $rev"
+ cache_set $rev $rev
+ done
+ fi
+
+ unrevs="$(find_existing_splits "$dir" "$revs")"
+
+ debug "git rev-list --reverse $revs $unrevs"
+ git rev-list --reverse --parents $revs $unrevsx |
while read rev parents; do
- newparents=$(cache_get $parents)
debug
- debug "Processing commit: $rev / $newparents"
+ debug "Processing commit: $rev"
+ exists=$(cache_get $rev)
+ if [ -n "$exists" ]; then
+ debug " prior: $exists"
+ continue
+ fi
+ debug " parents: $parents"
+ newparents=$(cache_get $parents)
+ debug " newparents: $newparents"
git ls-tree $rev -- "$dir" |
while read mode type tree name; do
for parent in $newparents; do
p="$p -p $parent"
done
- newrev=$(echo synthetic | git commit-tree $tree $p) \
- || die "Can't create new commit for $rev / $tree"
- echo " newrev is: $newrev"
+
+ newrev=$(copy_commit $rev $tree "$p") || exit $?
+ debug " newrev is: $newrev"
cache_set $rev $newrev
+ cache_set latest_new $newrev
+ cache_set latest_old $rev
done || exit $?
done || exit $?
+ latest_new=$(cache_get latest_new)
+ if [ -z "$latest_new" ]; then
+ die "No new revisions were found"
+ fi
+ if [ -n "$rejoin" ]; then
+ debug "Merging split branch into HEAD..."
+ latest_old=$(cache_get latest_old)
+ git merge -s ours \
+ -m "$(merge_msg $dir $latest_old $latest_new)" \
+ $latest_new
+ fi
+ echo $latest_new
exit 0
}