[PATCH/RFC 01/10] Teach rebase interactive the mark command

["Jörg Sommer" <joerg@alea.gnuu.de>]

This new command can be used to set symbolic marks for an commit while
doing a rebase. This symbolic name can later be used for merges or
resets.
---
 git-rebase--interactive.sh    |   36 ++++++++++++++++++++++++++++++++++++
 t/t3404-rebase-interactive.sh |   21 +++++++++++++++++++++
 2 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8aa7371..b001ddf 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -23,6 +23,7 @@ DONE="$DOTEST"/done
 MSG="$DOTEST"/message
 SQUASH_MSG="$DOTEST"/message-squash
 REWRITTEN="$DOTEST"/rewritten
+MARKS="$DOTEST"/marks
 PRESERVE_MERGES=
 STRATEGY=
 VERBOSE=
@@ -240,6 +241,23 @@ peek_next_command () {
 	sed -n "1s/ .*$//p" < "$TODO"
 }
 
+parse_mark() {
+	local tmp
+	tmp="$*"
+
+	case "$tmp" in
+	'#'[0-9]*)
+		tmp="${tmp#\#}"
+		if test "$tmp" = $(printf %d "$tmp")
+		then
+			echo $tmp
+			return 0
+		fi
+		;;
+	esac
+	return 1
+}
+
 do_next () {
 	rm -f "$DOTEST"/message "$DOTEST"/author-script \
 		"$DOTEST"/amend || exit
@@ -317,6 +335,23 @@ do_next () {
 			die_with_patch $sha1 ""
 		fi
 		;;
+	mark|a)
+		if ! mark=$(parse_mark $sha1)
+		then
+			warn "Invalid mark given: $command $sha1 $rest"
+			die_with_patch $sha1 \
+				"Please fix this in the file $TODO."
+		fi
+		mark_action_done
+
+		test -d "$MARKS" || mkdir "$MARKS"
+
+		test -e "$MARKS"/$mark && \
+			warn "mark $mark already exist; overwriting it"
+
+		git rev-parse --verify HEAD > "$MARKS"/$mark || \
+			die "HEAD is invalid"
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		die_with_patch $sha1 "Please fix this in the file $TODO."
@@ -533,6 +568,7 @@ do
 #  pick = use commit
 #  edit = use commit, but stop for amending
 #  squash = use commit, but meld into previous commit
+#  mark #NUM = mark the current HEAD for later reference
 #
 # If you remove a line here THAT COMMIT WILL BE LOST.
 # However, if you remove everything, the rebase will be aborted.
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9cf873f..4461674 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -82,6 +82,9 @@ for line in $FAKE_LINES; do
 	case $line in
 	squash|edit)
 		action="$line";;
+	mark*)
+		echo "mark ${line#mark}"
+		echo "mark ${line#mark}" >> "$1";;
 	*)
 		echo sed -n "${line}s/^pick/$action/p"
 		sed -n "${line}p" < "$1".tmp
@@ -189,6 +192,24 @@ test_expect_success '-p handles "no changes" gracefully' '
 	test $HEAD = $(git rev-parse HEAD)
 '
 
+test_expect_success 'setting an invalid mark fails' '
+	export FAKE_LINES="mark12 1" && \
+	test_must_fail git rebase -i HEAD~1 &&
+	unset FAKE_LINES &&
+	git rebase --abort
+'
+
+test_expect_success 'setting marks works' '
+	git checkout master &&
+	FAKE_LINES="mark#0 2 1 mark#42 3 edit 4" git rebase -i HEAD~4 &&
+	marks_dir=.git/.dotest-merge/marks
+	test -d $marks_dir &&
+	test $(ls $marks_dir | wc -l) -eq 2 &&
+	test "$(git rev-parse HEAD~4)" = "$(cat $marks_dir/0)" &&
+	test "$(git rev-parse HEAD~2)" = "$(cat $marks_dir/42)" &&
+	git rebase --abort
+'
+
 test_expect_success 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&
-- 
1.5.4.5