patch, 4 partsAdd a function for get the parents of a commit

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8aa7371..1b2381e 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -113,6 +113,22 @@ has_action () {
 	grep '^[^#]' "$1" >/dev/null
 }
 
+redo_merge() {
+	author_script=$(get_author_ident_from_commit $sha1)
+	eval "$author_script"
+	msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
+	if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
+		GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
+		GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
+		output git merge $STRATEGY -m "$msg" \
+			$new_parents
+	then
+		git rerere
+		printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
+		die Error redoing merge $sha1
+	fi
+}
+
 pick_one () {
 	no_ff=
 	case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
@@ -180,22 +196,9 @@ pick_one_preserving_merges () {
 		echo $sha1 > "$DOTEST"/current-commit
 		case "$new_parents" in
 		' '*' '*)
-			# redo merge
-			author_script=$(get_author_ident_from_commit $sha1)
-			eval "$author_script"
-			msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
 			# No point in merging the first parent, that's HEAD
 			new_parents=${new_parents# $first_parent}
-			if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
-				GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
-				GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
-				output git merge $STRATEGY -m "$msg" \
-					$new_parents
-			then
-				git rerere
-				printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
-				die Error redoing merge $sha1
-			fi
+			redo_merge
 			;;
 		*)
 			output git cherry-pick "$@" ||

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 1b2381e..ffd4823 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -114,14 +114,16 @@ has_action () {
 }
 
 redo_merge() {
-	author_script=$(get_author_ident_from_commit $sha1)
-	eval "$author_script"
+	sha1=$1
+	shift
+
+	eval "$(get_author_ident_from_commit $sha1)"
 	msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
+
 	if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
 		GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
 		GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
-		output git merge $STRATEGY -m "$msg" \
-			$new_parents
+		output git merge $STRATEGY -m "$msg" "$@"
 	then
 		git rerere
 		printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
@@ -197,8 +199,7 @@ pick_one_preserving_merges () {
 		case "$new_parents" in
 		' '*' '*)
 			# No point in merging the first parent, that's HEAD
-			new_parents=${new_parents# $first_parent}
-			redo_merge
+			redo_merge $sha1 ${new_parents# $first_parent}
 			;;
 		*)
 			output git cherry-pick "$@" ||

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index ffd4823..94c6827 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -131,6 +131,10 @@ redo_merge() {
 	fi
 }
 
+parents_of_commit() {
+	git rev-list --parents -1 "$1" | cut -d' ' -f2-
+}
+
 pick_one () {
 	no_ff=
 	case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
@@ -166,7 +170,7 @@ pick_one_preserving_merges () {
 	fast_forward=t
 	preserve=t
 	new_parents=
-	for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -f2-)
+	for p in $(parents_of_commit $sha1)
 	do
 		if test -f "$REWRITTEN"/$p
 		then

Documentation/git-rebase.txt, git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index e0412e0..354b6f0 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -11,6 +11,7 @@ SYNOPSIS
 'git-rebase' [-i | --interactive] [-v | --verbose] [-m | --merge]
 	[-s <strategy> | --strategy=<strategy>]
 	[-C<n>] [ --whitespace=<option>] [-p | --preserve-merges]
+	[-l | --linear-history]
 	[--onto <newbase>] <upstream> [<branch>]
 'git-rebase' --continue | --skip | --abort
 
@@ -247,6 +248,13 @@ OPTIONS
 	Instead of ignoring merges, try to recreate them.  This option
 	only works in interactive mode.
 
+-l, \--linear-history::
+	Use only commits of the branch they are not merged in, i.e.
+	follow only the first parent of a merge. Merges are part of this
+	list and they will be redone. It's possible to move merges in the
+	history forward and backward, but they can't take part on a join
+	(squash). This option only works in interactive mode.
+
 include::merge-strategies.txt[]
 
 NOTES
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 94c6827..a2a61f8 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -26,9 +26,11 @@ REWRITTEN="$DOTEST"/rewritten
 PRESERVE_MERGES=
 STRATEGY=
 VERBOSE=
+LINEAR_HISTORY=
 test -d "$REWRITTEN" && PRESERVE_MERGES=t
 test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
 test -f "$DOTEST"/verbose && VERBOSE=t
+test -f "$DOTEST"/linear_history && LINEAR_HISTORY=t
 
 GIT_CHERRY_PICK_HELP="  After resolving the conflicts,
 mark the corrected paths with 'git add <paths>', and
@@ -150,7 +152,18 @@ pick_one () {
 		sha1=$(git rev-parse --short $sha1)
 		output warn Fast forward to $sha1
 	else
-		output git cherry-pick "$@"
+		if test t = "$LINEAR_HISTORY" &&
+			other_parents="$(parents_of_commit $sha1 | cut -s -d' ' -f2-)" &&
+			test -n "$other_parents"
+		then
+			if test a"$1" = a-n
+			then
+				merge_opt=--no-commit
+			fi
+			redo_merge $sha1 $no_commit $other_parents
+		else
+			output git cherry-pick "$@"
+		fi
 	fi
 }
 
@@ -288,6 +301,11 @@ do_next () {
 		has_action "$DONE" ||
 			die "Cannot 'squash' without a previous commit"
 
+		test t = "$LINEAR_HISTORY" &&
+			( test "$(parents_of_commit HEAD |wc -w)" -gt 1 ||
+				 test "$(parents_of_commit $sha1 |wc -w)" -gt 1) &&
+			die "Joining a merge with a commit is not supported"
+
 		mark_action_done
 		make_squash_message $sha1 > "$MSG"
 		case "$(peek_next_command)" in
@@ -459,6 +477,9 @@ do
 	-i|--interactive)
 		# yeah, we know
 		;;
+	-l|--linear-history)
+		LINEAR_HISTORY=t
+		;;
 	''|-h)
 		usage
 		;;
@@ -522,6 +543,10 @@ do
 					die "Could not init rewritten commits"
 			done
 			MERGES_OPTION=
+		elif test t = "$LINEAR_HISTORY"
+		then
+			: > "$DOTEST"/linear_history
+			MERGES_OPTION=--first-parent
 		else
 			MERGES_OPTION=--no-merges
 		fi
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9cf873f..0476f6a 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -361,4 +361,76 @@ test_expect_success 'rebase with a file named HEAD in worktree' '
 
 '
 
+test_expect_success 'rebase linear history preserves merges' '
+	git tag linear-history-base to-be-preserved~2
+	git checkout -b linear-history linear-history-base &&
+	for i in 1 2 3
+	do
+		test $? -eq 0 &&
+		echo linear history test > lin-h-$i &&
+		git add lin-h-$i &&
+		test_tick &&
+	       	git commit -m "rebase linear history commit $i"
+	done
+	test_tick &&
+	git merge to-be-preserved &&
+	old_head=$(git rev-parse HEAD) &&
+	test_tick &&
+	EXPECT_COUNT=4 FAKE_LINES="2 4 edit 1 3" \
+		git rebase -v -i -l linear-history-base &&
+	EXPECT_COUNT=invalid git rebase --continue &&
+	test "$(git rev-list --parents -1 HEAD~2 | cut -d" " -f3-)" = \
+		"$(git rev-parse to-be-preserved)" &&
+	test "$(git show HEAD~2: | grep ^lin-h- | cut -c7- | tr -d \\012)" = 2 &&
+	test "$(git show HEAD~1: | grep ^lin-h- | cut -c7- | tr -d \\012)" = 12 &&
+	test "$(git cat-file commit HEAD | sed -n "/^tree/{p;q;}")" = \
+		"$(git cat-file commit $old_head | sed -n "/^tree/{p;q;}")"
+'
+
+test_expect_success 'rebase linear history is noop, if base = base' '
+	old_head=$(git rev-parse HEAD) &&
+	test_tick &&
+	EXPECT_COUNT=4 git rebase -v -i -l linear-history-base &&
+	test "$(git rev-parse HEAD)" = $old_head
+'
+
+test_expect_success 'ensure rebase linear history persits across edits' '
+	old_head=$(git rev-parse HEAD) &&
+	test_tick &&
+	EXPECT_COUNT=4 FAKE_LINES="edit 1 2 3 4" \
+		git rebase -v -i -l linear-history-base &&
+	EXPECT_COUNT=invalid git rebase --continue &&
+	test "$(git rev-parse HEAD)" = $old_head
+'
+
+test_str='test_tick &&
+	(
+		outp=$(test_must_fail git rebase -v -i -l HEAD~3 2>&1)
+		rc=$?
+		echo "$outp"
+        	echo "$outp" | grep "^Joining .* not supported\$" >/dev/null &&
+		return $rc
+	) &&
+	git rebase --abort'
+
+test_expect_success 'rebase linear with squashing a merge fails' "
+	export EXPECT_COUNT=3 FAKE_LINES='1 squash 2 3' &&
+	$test_str &&
+	FAKE_LINES='2 squash 1 3' &&
+	$test_str
+"
+
+test_expect_success 'rebase linear history does a fast forward' '
+	old_head=$(git rev-parse HEAD) &&
+	test_tick &&
+	EXPECT_COUNT=4 FAKE_LINES="2 3 4 1" \
+		git rebase -v -i -l linear-history-base &&
+	test "$(git rev-parse HEAD~3)" = "$(git rev-parse to-be-preserved)" &&
+	test "$(git show HEAD~2: | grep ^lin-h- | cut -c7- | tr -d \\012)" = 1 &&
+	test "$(git show HEAD~1: | grep ^lin-h- | cut -c7- | tr -d \\012)" = 13 &&
+	test -z "$(git rev-list --parents -1 HEAD~3 | cut -d" " -f3-)" &&
+	test "$(git cat-file commit HEAD | sed -n "/^tree/{p;q;}")" = \
+		"$(git cat-file commit $old_head | sed -n "/^tree/{p;q;}")"
+'
+
 test_done

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

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 &&

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index b001ddf..7dac51b 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -258,6 +258,16 @@ parse_mark() {
 	return 1
 }
 
+mark_to_sha1() {
+	local mark
+	if mark=$(parse_mark $1)
+	then
+		cat "$MARKS"/$mark
+	else
+		return 1
+	fi
+}
+
 do_next () {
 	rm -f "$DOTEST"/message "$DOTEST"/author-script \
 		"$DOTEST"/amend || exit
@@ -352,6 +362,15 @@ do_next () {
 		git rev-parse --verify HEAD > "$MARKS"/$mark || \
 			die "HEAD is invalid"
 		;;
+	reset|r)
+		comment_for_reflog reset
+
+		mark_action_done
+		tmp=$(mark_to_sha1 $sha1) || \
+			tmp=$(git rev-parse --verify $sha1) ||
+			die "Invalid parent '$sha1' in $command $sha1 $rest"
+		output git reset --hard $tmp
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		die_with_patch $sha1 "Please fix this in the file $TODO."
@@ -569,6 +588,7 @@ do
 #  edit = use commit, but stop for amending
 #  squash = use commit, but meld into previous commit
 #  mark #NUM = mark the current HEAD for later reference
+#  reset #NUM|commit = reset HEAD to a previous set mark or a commit
 #
 # 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 4461674..521206f 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -85,6 +85,9 @@ for line in $FAKE_LINES; do
 	mark*)
 		echo "mark ${line#mark}"
 		echo "mark ${line#mark}" >> "$1";;
+	reset*)
+		echo "reset ${line#reset}"
+		echo "reset ${line#reset}" >> "$1";;
 	*)
 		echo sed -n "${line}s/^pick/$action/p"
 		sed -n "${line}p" < "$1".tmp
@@ -210,6 +213,13 @@ test_expect_success 'setting marks works' '
 	git rebase --abort
 '
 
+test_expect_success 'reset with nonexistent mark fails' '
+	export FAKE_LINES="reset#0 1" &&
+	test_must_fail git rebase -i HEAD~1 &&
+	unset FAKE_LINES &&
+	git rebase --abort
+'
+
 test_expect_success 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 7dac51b..18cdf3d 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -362,6 +362,29 @@ do_next () {
 		git rev-parse --verify HEAD > "$MARKS"/$mark || \
 			die "HEAD is invalid"
 		;;
+	merge|m)
+		comment_for_reflog merge
+
+		if ! git rev-parse --verify $sha1
+		then
+			die "Invalid reference merge '$sha1' in $command $sha1 $rest"
+		fi
+
+		new_parents=
+		for p in $rest
+		do
+			tmp=$(mark_to_sha1 $p) || \
+				tmp=$(git rev-parse --verify $p) ||
+				die "Invalid parent '$sha1' in $command $sha1 $rest"
+			new_parents="$new_parents $tmp"
+		done
+		new_parents="${new_parents# }"
+		test -n "$new_parents" || \
+			die "You forgot to give the parents for the merge"
+
+		mark_action_done
+		redo_merge $sha1 $new_parents
+		;;
 	reset|r)
 		comment_for_reflog reset
 
@@ -589,6 +612,8 @@ do
 #  squash = use commit, but meld into previous commit
 #  mark #NUM = mark the current HEAD for later reference
 #  reset #NUM|commit = reset HEAD to a previous set mark or a commit
+#  merge commit-M #NUM|commit-P ... = redo merge commit-M with the
+#         current HEAD and the parents marked with #NUM or the commit-P
 #
 # 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 521206f..892fd5d 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -88,6 +88,9 @@ for line in $FAKE_LINES; do
 	reset*)
 		echo "reset ${line#reset}"
 		echo "reset ${line#reset}" >> "$1";;
+	merge*)
+		echo "merge ${line#merge}" | tr / ' '
+		echo "merge ${line#merge}" | tr / ' ' >> "$1";;
 	*)
 		echo sed -n "${line}s/^pick/$action/p"
 		sed -n "${line}p" < "$1".tmp

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 18cdf3d..973770e 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -114,6 +114,22 @@ has_action () {
 	grep '^[^#]' "$1" >/dev/null
 }
 
+redo_merge() {
+	author_script=$(get_author_ident_from_commit $sha1)
+	eval "$author_script"
+	msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
+	if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
+		GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
+		GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
+		output git merge $STRATEGY -m "$msg" \
+			$new_parents
+	then
+		git rerere
+		printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
+		die Error redoing merge $sha1
+	fi
+}
+
 pick_one () {
 	no_ff=
 	case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
@@ -181,22 +197,9 @@ pick_one_preserving_merges () {
 		echo $sha1 > "$DOTEST"/current-commit
 		case "$new_parents" in
 		' '*' '*)
-			# redo merge
-			author_script=$(get_author_ident_from_commit $sha1)
-			eval "$author_script"
-			msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
 			# No point in merging the first parent, that's HEAD
 			new_parents=${new_parents# $first_parent}
-			if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
-				GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
-				GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
-				output git merge $STRATEGY -m "$msg" \
-					$new_parents
-			then
-				git rerere
-				printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
-				die Error redoing merge $sha1
-			fi
+			redo_merge
 			;;
 		*)
 			output git cherry-pick "$@" ||

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 973770e..1698c3e 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -115,14 +115,17 @@ has_action () {
 }
 
 redo_merge() {
-	author_script=$(get_author_ident_from_commit $sha1)
-	eval "$author_script"
+	local sha1
+	sha1=$1
+	shift
+
+	eval "$(get_author_ident_from_commit $sha1)"
 	msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
+
 	if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
 		GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
 		GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
-		output git merge $STRATEGY -m "$msg" \
-			$new_parents
+		output git merge $STRATEGY -m "$msg" "$@"
 	then
 		git rerere
 		printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
@@ -198,8 +201,7 @@ pick_one_preserving_merges () {
 		case "$new_parents" in
 		' '*' '*)
 			# No point in merging the first parent, that's HEAD
-			new_parents=${new_parents# $first_parent}
-			redo_merge
+			redo_merge $sha1 ${new_parents# $first_parent}
 			;;
 		*)
 			output git cherry-pick "$@" ||

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 1698c3e..060b40f 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -600,9 +600,9 @@ do
 			MERGES_OPTION=--no-merges
 		fi
 
-		SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
-		SHORTHEAD=$(git rev-parse --short $HEAD)
-		SHORTONTO=$(git rev-parse --short $ONTO)
+		SHORTUPSTREAM=$(git rev-parse --short=7 $UPSTREAM)
+		SHORTHEAD=$(git rev-parse --short=7 $HEAD)
+		SHORTONTO=$(git rev-parse --short=7 $ONTO)
 		git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
 			--abbrev=7 --reverse --left-right --cherry-pick \
 			$UPSTREAM...$HEAD | \

diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 892fd5d..aa4bb8d 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -73,7 +73,7 @@ esac
 test -z "$EXPECT_COUNT" ||
 	test "$EXPECT_COUNT" = $(sed -e '/^#/d' -e '/^$/d' < "$1" | wc -l) ||
 	exit
-test -z "$FAKE_LINES" && exit
+test -z "$FAKE_LINES" && { grep -v '^#' "$1"; exit; }
 grep -v '^#' < "$1" > "$1".tmp
 rm -f "$1"
 cat "$1".tmp

diff --git a/git-merge.sh b/git-merge.sh
index 7dbbb1d..bd9699d 100755
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -250,17 +250,19 @@ else
 	# We are invoked directly as the first-class UI.
 	head_arg=HEAD
 
-	# All the rest are the commits being merged; prepare
-	# the standard merge summary message to be appended to
-	# the given message.  If remote is invalid we will die
-	# later in the common codepath so we discard the error
-	# in this loop.
-	merge_name=$(for remote
-		do
-			merge_name "$remote"
-		done | git fmt-merge-msg
-	)
-	merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
+	if test -z "$merge_msg"
+	then
+		# All the rest are the commits being merged; prepare
+		# the standard merge summary message to be appended to
+		# the given message.  If remote is invalid we will die
+		# later in the common codepath so we discard the error
+		# in this loop.
+		merge_msg=$(for remote
+			do
+				merge_name "$remote"
+			done | git fmt-merge-msg
+		)
+	fi
 fi
 head=$(git rev-parse --verify "$head_arg"^0) || usage
 

diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index aa4bb8d..be26a78 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -92,9 +92,8 @@ for line in $FAKE_LINES; do
 		echo "merge ${line#merge}" | tr / ' '
 		echo "merge ${line#merge}" | tr / ' ' >> "$1";;
 	*)
-		echo sed -n "${line}s/^pick/$action/p"
-		sed -n "${line}p" < "$1".tmp
-		sed -n "${line}s/^pick/$action/p" < "$1".tmp >> "$1"
+		sed -n "${line}{s/^pick/$action/; p;}" < "$1".tmp
+		sed -n "${line}{s/^pick/$action/; p;}" < "$1".tmp >> "$1"
 		action=pick;;
 	esac
 done

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 060b40f..27bd87e 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -22,12 +22,10 @@ TODO="$DOTEST"/git-rebase-todo
 DONE="$DOTEST"/done
 MSG="$DOTEST"/message
 SQUASH_MSG="$DOTEST"/message-squash
-REWRITTEN="$DOTEST"/rewritten
 MARKS="$DOTEST"/marks
 PRESERVE_MERGES=
 STRATEGY=
 VERBOSE=
-test -d "$REWRITTEN" && PRESERVE_MERGES=t
 test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
 test -f "$DOTEST"/verbose && VERBOSE=t
 
@@ -137,8 +135,6 @@ pick_one () {
 	no_ff=
 	case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
 	output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
-	test -d "$REWRITTEN" &&
-		pick_one_preserving_merges "$@" && return
 	parent_sha1=$(git rev-parse --verify $sha1^) ||
 		die "Could not get the parent of $sha1"
 	current_sha1=$(git rev-parse --verify HEAD)
@@ -152,66 +148,6 @@ pick_one () {
 	fi
 }
 
-pick_one_preserving_merges () {
-	case "$1" in -n) sha1=$2 ;; *) sha1=$1 ;; esac
-	sha1=$(git rev-parse $sha1)
-
-	if test -f "$DOTEST"/current-commit
-	then
-		current_commit=$(cat "$DOTEST"/current-commit) &&
-		git rev-parse HEAD > "$REWRITTEN"/$current_commit &&
-		rm "$DOTEST"/current-commit ||
-		die "Cannot write current commit's replacement sha1"
-	fi
-
-	# rewrite parents; if none were rewritten, we can fast-forward.
-	fast_forward=t
-	preserve=t
-	new_parents=
-	for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -f2-)
-	do
-		if test -f "$REWRITTEN"/$p
-		then
-			preserve=f
-			new_p=$(cat "$REWRITTEN"/$p)
-			test $p != $new_p && fast_forward=f
-			case "$new_parents" in
-			*$new_p*)
-				;; # do nothing; that parent is already there
-			*)
-				new_parents="$new_parents $new_p"
-				;;
-			esac
-		fi
-	done
-	case $fast_forward in
-	t)
-		output warn "Fast forward to $sha1"
-		test $preserve = f || echo $sha1 > "$REWRITTEN"/$sha1
-		;;
-	f)
-		test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
-
-		first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
-		# detach HEAD to current parent
-		output git checkout $first_parent 2> /dev/null ||
-			die "Cannot move HEAD to $first_parent"
-
-		echo $sha1 > "$DOTEST"/current-commit
-		case "$new_parents" in
-		' '*' '*)
-			# No point in merging the first parent, that's HEAD
-			redo_merge $sha1 ${new_parents# $first_parent}
-			;;
-		*)
-			output git cherry-pick "$@" ||
-				die_with_patch $sha1 "Could not pick $sha1"
-			;;
-		esac
-		;;
-	esac
-}
-
 nth_string () {
 	case "$1" in
 	*1[0-9]|*[04-9]) echo "$1"th;;
@@ -410,20 +346,7 @@ do_next () {
 	HEADNAME=$(cat "$DOTEST"/head-name) &&
 	OLDHEAD=$(cat "$DOTEST"/head) &&
 	SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) &&
-	if test -d "$REWRITTEN"
-	then
-		test -f "$DOTEST"/current-commit &&
-			current_commit=$(cat "$DOTEST"/current-commit) &&
-			git rev-parse HEAD > "$REWRITTEN"/$current_commit
-		if test -f "$REWRITTEN"/$OLDHEAD
-		then
-			NEWHEAD=$(cat "$REWRITTEN"/$OLDHEAD)
-		else
-			NEWHEAD=$OLDHEAD
-		fi
-	else
-		NEWHEAD=$(git rev-parse HEAD)
-	fi &&
+	NEWHEAD=$(git rev-parse HEAD) &&
 	case $HEADNAME in
 	refs/*)
 		message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO)" &&
@@ -448,6 +371,138 @@ do_rest () {
 	done
 }
 
+sha1_to_mark() {
+	# args: "sha1" " sha1#mark sha1#mark"
+	local tmp
+	case "$2" in
+	*" $1#"*)
+		tmp="${2#* $1#}"
+		echo "${tmp%% *}"
+		;;
+	*)
+		return 1
+		;;
+	esac
+}
+
+insert_sha1_with_mark_in_list() {
+	# args: "sha1" "mark" " sha1#mark sha1#mark"
+	case "$3" in
+	*" $1#"*)
+		echo "$3"
+		return 1
+		;;
+	*)
+		echo "$3 $1#$2"
+		;;
+	esac
+}
+
+create_extended_todo_list() {
+	(
+	while IFS=_ read commit parents subject
+	do
+		if test "${last_parent:-$commit}" != "$commit"
+		then
+			if test t = "${delayed_mark:-f}"
+			then
+				case "${marked_commits:-} " in
+				*" $last_parent ")
+					;;
+				*)
+					marked_commits="${marked_commits:-} $last_parent"
+					;;
+				esac
+				delayed_mark=f
+			fi
+			test "$last_parent" = $SHORTUPSTREAM && \
+				last_parent=$SHORTONTO
+			echo "reset $last_parent"
+		fi
+		last_parent="${parents%% *}"
+
+		case "${marked_commits:-} " in
+		*" $commit "*)
+			echo mark
+			;;
+		esac
+
+		case "$parents" in
+		*' '*)
+			delayed_mark=t
+			new_parents=
+			for p in ${parents#* }
+			do
+				case "${marked_commits:-} " in
+				*" $p ")
+					;;
+				*)
+					marked_commits="${marked_commits:-} $p"
+					;;
+				esac
+				if test "$p" = $SHORTUPSTREAM
+				then
+					new_parents="$new_parents $SHORTONTO"
+				else
+					new_parents="$new_parents $p"
+				fi
+			done
+			unset p
+			echo merge $commit $new_parents
+			unset new_parents
+			;;
+		*)
+			echo "pick $commit $subject"
+			;;
+		esac
+	done
+	test -n "${last_parent:-}" -a "${last_parent:-}" != $SHORTUPSTREAM && \
+		echo reset $last_parent
+	) | \
+	tac | \
+	while read cmd args
+	do
+		: ${commit_mark_list:=} ${last_commit:=000}
+		case "$cmd" in
+		pick)
+			last_commit="${args%% *}"
+			;;
+		mark)
+			: ${next_mark:=0}
+			if commit_mark_list=$(insert_sha1_with_mark_in_list \
+				$last_commit $next_mark "$commit_mark_list")
+			then
+				args="#$next_mark"
+				next_mark=$(($next_mark + 1))
+			else
+				die "Internal error: two marks for the same commit"
+			fi
+			;;
+		reset)
+			if tmp=$(sha1_to_mark $args "$commit_mark_list")
+			then
+				args="#$tmp"
+			fi
+			;;
+		merge)
+			new_args=
+			for i in ${args#* }
+			do
+				if tmp=$(sha1_to_mark $i "$commit_mark_list")
+				then
+					new_args="$new_args #$tmp"
+				else
+					new_args="$new_args $i"
+				fi
+			done
+			last_commit="${args%% *}"
+			args="$last_commit ${new_args# }"
+			;;
+		esac
+		echo "$cmd $args"
+	done
+}
+
 while test $# != 0
 do
 	case "$1" in
@@ -580,33 +635,24 @@ do
 		echo $ONTO > "$DOTEST"/onto
 		test -z "$STRATEGY" || echo "$STRATEGY" > "$DOTEST"/strategy
 		test t = "$VERBOSE" && : > "$DOTEST"/verbose
-		if test t = "$PRESERVE_MERGES"
-		then
-			# $REWRITTEN contains files for each commit that is
-			# reachable by at least one merge base of $HEAD and
-			# $UPSTREAM. They are not necessarily rewritten, but
-			# their children might be.
-			# This ensures that commits on merged, but otherwise
-			# unrelated side branches are left alone. (Think "X"
-			# in the man page's example.)
-			mkdir "$REWRITTEN" &&
-			for c in $(git merge-base --all $HEAD $UPSTREAM)
-			do
-				echo $ONTO > "$REWRITTEN"/$c ||
-					die "Could not init rewritten commits"
-			done
-			MERGES_OPTION=
-		else
-			MERGES_OPTION=--no-merges
-		fi
 
 		SHORTUPSTREAM=$(git rev-parse --short=7 $UPSTREAM)
 		SHORTHEAD=$(git rev-parse --short=7 $HEAD)
 		SHORTONTO=$(git rev-parse --short=7 $ONTO)
-		git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
-			--abbrev=7 --reverse --left-right --cherry-pick \
-			$UPSTREAM...$HEAD | \
-			sed -n "s/^>/pick /p" > "$TODO"
+		common_rev_parse_opts="--abbrev-commit
+			--abbrev=7 --left-right --cherry-pick
+			$UPSTREAM...$HEAD"
+		if test t = "$PRESERVE_MERGES"
+		then
+			git rev-list --pretty='format:%h_%p_%s' \
+				--topo-order $common_rev_parse_opts | \
+				grep -v ^commit | \
+				create_extended_todo_list
+		else
+			git rev-list --no-merges --reverse --pretty=oneline \
+				$common_rev_parse_opts | sed -n "s/^>/pick /p"
+		fi > "$TODO"
+
 		cat >> "$TODO" << EOF
 
 # Rebase $SHORTUPSTREAM..$SHORTHEAD onto $SHORTONTO
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index be26a78..af7d818 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -245,7 +245,41 @@ test_expect_success 'preserve merges with -p' '
 	test $(git show HEAD~2:file1) = B
 '
 
+test_expect_success 'rebase with preserve merge forth and back is a noop' '
+	git checkout -b big-branch-1 master &&
+	: > bb1a &&
+	git add bb1a &&
+	git commit -m "big branch commit 1" &&
+	: > bb1b &&
+	git add bb1b &&
+	git commit -m "big branch commit 2" &&
+	: > bb1c &&
+	git add bb1c &&
+	git commit -m "big branch commit 3" &&
+	git checkout -b big-branch-2 master &&
+	: > bb2a &&
+	git add bb2a &&
+	git commit -m "big branch commit 4" &&
+	: > bb2b &&
+	git add bb2b &&
+	git commit -m "big branch commit 5" &&
+	git merge big-branch-1~1 &&
+	git merge to-be-preserved &&
+	tbp_merge=$(git rev-parse HEAD) &&
+	: > bb2c &&
+	git add bb2c &&
+	git commit -m "big branch commit 6" &&
+	git merge big-branch-1 &&
+	head=$(git rev-parse HEAD) &&
+	FAKE_LINES="16 6 19 20 4 1 2 5 22" \
+		git rebase -i -p --onto dead-end master &&
+	FAKE_LINES="3 7 mark#10 8 9 5 1 2 merge$tbp_merge~1/#10 merge$tbp_merge/to-be-preserved 6 11" \
+	git rebase -i -p --onto master dead-end &&
+	test "$head" = "$(git rev-parse HEAD)"
+'
+
 test_expect_success '--continue tries to commit' '
+	git checkout to-be-rebased &&
 	test_tick &&
 	! git rebase -i --onto new-branch1 HEAD^ &&
 	echo resolved > file1 &&

diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9cf873f..8d29878 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -73,7 +73,7 @@ esac
 test -z "$EXPECT_COUNT" ||
 	test "$EXPECT_COUNT" = $(sed -e '/^#/d' -e '/^$/d' < "$1" | wc -l) ||
 	exit
-test -z "$FAKE_LINES" && exit
+test -z "$FAKE_LINES" && { grep -v '^#' "$1"; exit; }
 grep -v '^#' < "$1" > "$1".tmp
 rm -f "$1"
 cat "$1".tmp

diff --git a/git-merge.sh b/git-merge.sh
index 7dbbb1d..bd9699d 100755
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -250,17 +250,19 @@ else
 	# We are invoked directly as the first-class UI.
 	head_arg=HEAD
 
-	# All the rest are the commits being merged; prepare
-	# the standard merge summary message to be appended to
-	# the given message.  If remote is invalid we will die
-	# later in the common codepath so we discard the error
-	# in this loop.
-	merge_name=$(for remote
-		do
-			merge_name "$remote"
-		done | git fmt-merge-msg
-	)
-	merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
+	if test -z "$merge_msg"
+	then
+		# All the rest are the commits being merged; prepare
+		# the standard merge summary message to be appended to
+		# the given message.  If remote is invalid we will die
+		# later in the common codepath so we discard the error
+		# in this loop.
+		merge_msg=$(for remote
+			do
+				merge_name "$remote"
+			done | git fmt-merge-msg
+		)
+	fi
 fi
 head=$(git rev-parse --verify "$head_arg"^0) || usage
 

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 8aa7371..531ee94 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -104,8 +104,12 @@ die_with_patch () {
 	die "$2"
 }
 
-die_abort () {
+cleanup_before_quit () {
 	rm -rf "$DOTEST"
+}
+
+die_abort () {
+	cleanup_before_quit
 	die "$1"
 }
 
@@ -352,7 +356,7 @@ do_next () {
 		test ! -f "$DOTEST"/verbose ||
 			git diff-tree --stat $(cat "$DOTEST"/head)..HEAD
 	} &&
-	rm -rf "$DOTEST" &&
+	cleanup_before_quit &&
 	git gc --auto &&
 	warn "Successfully rebased and updated $HEADNAME."
 
@@ -414,7 +418,7 @@ do
 			;;
 		esac &&
 		output git reset --hard $HEAD &&
-		rm -rf "$DOTEST"
+		cleanup_before_quit
 		exit
 		;;
 	--skip)

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 531ee94..6ac316a 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -35,6 +35,8 @@ mark the corrected paths with 'git add <paths>', and
 run 'git rebase --continue'"
 export GIT_CHERRY_PICK_HELP
 
+mark_prefix=refs/rebase-marks/
+
 warn () {
 	echo "$*" >&2
 }
@@ -105,7 +107,13 @@ die_with_patch () {
 }
 
 cleanup_before_quit () {
-	rm -rf "$DOTEST"
+	rm -rf "$DOTEST" &&
+	for ref in "$GIT_DIR/$mark_prefix"*
+	do
+		test "$ref" = "$GIT_DIR/$mark_prefix*" && continue
+		git update-ref -d "${ref#$GIT_DIR/}" "${ref#$GIT_DIR/}" || \
+			return 1
+	done
 }
 
 die_abort () {
@@ -244,6 +252,19 @@ peek_next_command () {
 	sed -n "1s/ .*$//p" < "$TODO"
 }
 
+mark_to_ref () {
+	case "$1" in
+	:[!/]*)
+		# :/SOMETHING is a reference for the last commit whose
+                # message starts with SOMETHING
+		echo "$mark_prefix${1#:}"
+		;;
+	*)
+		echo "$1"
+		;;
+	esac
+}
+
 do_next () {
 	rm -f "$DOTEST"/message "$DOTEST"/author-script \
 		"$DOTEST"/amend || exit
@@ -321,6 +342,15 @@ do_next () {
 			die_with_patch $sha1 ""
 		fi
 		;;
+	mark)
+		mark_action_done
+
+		mark=$(mark_to_ref :${sha1#:})
+		git rev-parse --verify "$mark" > /dev/null 2>&1 && \
+			warn "mark $sha1 already exist; overwriting it"
+
+		git update-ref "$mark" HEAD || die "update-ref failed"
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		die_with_patch $sha1 "Please fix this in the file $TODO."
@@ -533,10 +563,15 @@ do
 
 # Rebase $SHORTUPSTREAM..$SHORTHEAD onto $SHORTONTO
 #
+# In the todo insn whenever you need to refer to a commit, in addition
+# to the usual commit object name, you can use ':mark' syntax to refer
+# to a commit previously marked with the 'mark' insn.
+#
 # Commands:
 #  pick = use commit
 #  edit = use commit, but stop for amending
 #  squash = use commit, but meld into previous commit
+#  mark :mark = 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 8d29878..fa3560e 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 +192,20 @@ test_expect_success '-p handles "no changes" gracefully' '
 	test $HEAD = $(git rev-parse HEAD)
 '
 
+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/refs/rebase-marks &&
+	test -d $marks_dir &&
+	test $(ls $marks_dir | wc -l) -eq 2 &&
+	test "$(git rev-parse HEAD~4)" = \
+		"$(git rev-parse refs/rebase-marks/0)" &&
+	test "$(git rev-parse HEAD~2)" = \
+		"$(git rev-parse refs/rebase-marks/42)" &&
+	git rebase --abort &&
+	ls $marks_dir | wc -l | grep -Fx 0
+'
+
 test_expect_success 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 6ac316a..a4b7aad 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -351,6 +351,15 @@ do_next () {
 
 		git update-ref "$mark" HEAD || die "update-ref failed"
 		;;
+	reset|r)
+		comment_for_reflog reset
+
+		tmp=$(git rev-parse --verify "$(mark_to_ref $sha1)") ||
+			die "Invalid parent '$sha1' in $command $sha1 $rest"
+
+		mark_action_done
+		output git reset --hard $tmp
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		die_with_patch $sha1 "Please fix this in the file $TODO."
@@ -572,6 +581,7 @@ do
 #  edit = use commit, but stop for amending
 #  squash = use commit, but meld into previous commit
 #  mark :mark = mark the current HEAD for later reference
+#  reset commit = reset HEAD to the commit
 #
 # 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 fa3560e..78673a6 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -85,6 +85,9 @@ for line in $FAKE_LINES; do
 	mark*)
 		echo "mark ${line#mark}"
 		echo "mark ${line#mark}" >> "$1";;
+	reset*)
+		echo "reset ${line#reset}"
+		echo "reset ${line#reset}" >> "$1";;
 	*)
 		echo sed -n "${line}s/^pick/$action/p"
 		sed -n "${line}p" < "$1".tmp
@@ -206,6 +209,20 @@ test_expect_success 'setting marks works' '
 	ls $marks_dir | wc -l | grep -Fx 0
 '
 
+test_expect_success 'reset with nonexistent mark fails' '
+	export FAKE_LINES="reset:0 1" &&
+	test_must_fail git rebase -i HEAD~1 &&
+	unset FAKE_LINES &&
+	git rebase --abort
+'
+
+test_expect_success 'reset to HEAD is a nop' '
+	test_tick &&
+	head=$(git rev-parse --short HEAD) &&
+	FAKE_LINES="reset$head" git rebase -i HEAD~4 &&
+	test "$(git rev-parse --short HEAD)" = "$head"
+'
+
 test_expect_success 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index a4b7aad..19145b1 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -125,6 +125,25 @@ has_action () {
 	grep '^[^#]' "$1" >/dev/null
 }
 
+redo_merge () {
+	rm_sha1=$1
+	shift
+
+	eval "$(get_author_ident_from_commit $rm_sha1)"
+	msg="$(git cat-file commit $rm_sha1 | sed -e '1,/^$/d')"
+
+	if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
+		GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
+		GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
+		output git merge $STRATEGY -m "$msg" "$@"
+	then
+		git rerere
+		printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
+		die Error redoing merge $rm_sha1
+	fi
+	unset rm_sha1
+}
+
 pick_one () {
 	no_ff=
 	case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
@@ -192,22 +211,8 @@ pick_one_preserving_merges () {
 		echo $sha1 > "$DOTEST"/current-commit
 		case "$new_parents" in
 		' '*' '*)
-			# redo merge
-			author_script=$(get_author_ident_from_commit $sha1)
-			eval "$author_script"
-			msg="$(git cat-file commit $sha1 | sed -e '1,/^$/d')"
 			# No point in merging the first parent, that's HEAD
-			new_parents=${new_parents# $first_parent}
-			if ! GIT_AUTHOR_NAME="$GIT_AUTHOR_NAME" \
-				GIT_AUTHOR_EMAIL="$GIT_AUTHOR_EMAIL" \
-				GIT_AUTHOR_DATE="$GIT_AUTHOR_DATE" \
-				output git merge $STRATEGY -m "$msg" \
-					$new_parents
-			then
-				git rerere
-				printf "%s\n" "$msg" > "$GIT_DIR"/MERGE_MSG
-				die Error redoing merge $sha1
-			fi
+			redo_merge $sha1 ${new_parents# $first_parent}
 			;;
 		*)
 			output git cherry-pick "$@" ||

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 19145b1..fd41ca0 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -356,6 +356,28 @@ do_next () {
 
 		git update-ref "$mark" HEAD || die "update-ref failed"
 		;;
+	merge|m)
+		comment_for_reflog merge
+
+		if ! git rev-parse --verify $sha1 > /dev/null
+		then
+			die "Invalid reference merge '$sha1' in"
+					"$command $sha1 $rest"
+		fi
+
+		new_parents=
+		for p in $rest
+		do
+			new_parents="$new_parents $(mark_to_ref $p)"
+		done
+		new_parents="${new_parents# }"
+		test -n "$new_parents" || \
+			die "You forgot to give the parents for the" \
+				"merge $sha1. Please fix it in $TODO"
+
+		mark_action_done
+		redo_merge $sha1 $new_parents
+		;;
 	reset|r)
 		comment_for_reflog reset
 
@@ -587,6 +609,8 @@ do
 #  squash = use commit, but meld into previous commit
 #  mark :mark = mark the current HEAD for later reference
 #  reset commit = reset HEAD to the commit
+#  merge commit-M commit-P ... = redo merge commit-M with the
+#         current HEAD and the parents commit-P
 #
 # 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 78673a6..ceb9d74 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -88,6 +88,9 @@ for line in $FAKE_LINES; do
 	reset*)
 		echo "reset ${line#reset}"
 		echo "reset ${line#reset}" >> "$1";;
+	merge*)
+		echo "merge ${line#merge}" | tr / ' '
+		echo "merge ${line#merge}" | tr / ' ' >> "$1";;
 	*)
 		echo sed -n "${line}s/^pick/$action/p"
 		sed -n "${line}p" < "$1".tmp
@@ -223,6 +226,16 @@ test_expect_success 'reset to HEAD is a nop' '
 	test "$(git rev-parse --short HEAD)" = "$head"
 '
 
+test_expect_success 'merge redoes merges' '
+	test_tick &&
+	git merge dead-end &&
+	merge=$(git rev-parse HEAD) &&
+	git reset --hard HEAD~1 &&
+	FAKE_LINES="1 merge$merge/dead-end" git rebase -i HEAD~1 &&
+	test $merge = "$(git rev-parse HEAD)" &&
+	git reset --hard HEAD~1
+'
+
 test_expect_success 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index fd41ca0..d0a7e5c 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -588,9 +588,9 @@ do
 			MERGES_OPTION=--no-merges
 		fi
 
-		SHORTUPSTREAM=$(git rev-parse --short $UPSTREAM)
-		SHORTHEAD=$(git rev-parse --short $HEAD)
-		SHORTONTO=$(git rev-parse --short $ONTO)
+		SHORTUPSTREAM=$(git rev-parse --short=7 $UPSTREAM)
+		SHORTHEAD=$(git rev-parse --short=7 $HEAD)
+		SHORTONTO=$(git rev-parse --short=7 $ONTO)
 		git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
 			--abbrev=7 --reverse --left-right --cherry-pick \
 			$UPSTREAM...$HEAD | \

diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index ceb9d74..0a8d065 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -92,9 +92,8 @@ for line in $FAKE_LINES; do
 		echo "merge ${line#merge}" | tr / ' '
 		echo "merge ${line#merge}" | tr / ' ' >> "$1";;
 	*)
-		echo sed -n "${line}s/^pick/$action/p"
-		sed -n "${line}p" < "$1".tmp
-		sed -n "${line}s/^pick/$action/p" < "$1".tmp >> "$1"
+		sed -n "${line}{s/^pick/$action/; p;}" < "$1".tmp
+		sed -n "${line}{s/^pick/$action/; p;}" < "$1".tmp >> "$1"
 		action=pick;;
 	esac
 done

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index d0a7e5c..d3327a8 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -22,11 +22,9 @@ TODO="$DOTEST"/git-rebase-todo
 DONE="$DOTEST"/done
 MSG="$DOTEST"/message
 SQUASH_MSG="$DOTEST"/message-squash
-REWRITTEN="$DOTEST"/rewritten
 PRESERVE_MERGES=
 STRATEGY=
 VERBOSE=
-test -d "$REWRITTEN" && PRESERVE_MERGES=t
 test -f "$DOTEST"/strategy && STRATEGY="$(cat "$DOTEST"/strategy)"
 test -f "$DOTEST"/verbose && VERBOSE=t
 
@@ -148,8 +146,6 @@ pick_one () {
 	no_ff=
 	case "$1" in -n) sha1=$2; no_ff=t ;; *) sha1=$1 ;; esac
 	output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
-	test -d "$REWRITTEN" &&
-		pick_one_preserving_merges "$@" && return
 	parent_sha1=$(git rev-parse --verify $sha1^) ||
 		die "Could not get the parent of $sha1"
 	current_sha1=$(git rev-parse --verify HEAD)
@@ -163,66 +159,6 @@ pick_one () {
 	fi
 }
 
-pick_one_preserving_merges () {
-	case "$1" in -n) sha1=$2 ;; *) sha1=$1 ;; esac
-	sha1=$(git rev-parse $sha1)
-
-	if test -f "$DOTEST"/current-commit
-	then
-		current_commit=$(cat "$DOTEST"/current-commit) &&
-		git rev-parse HEAD > "$REWRITTEN"/$current_commit &&
-		rm "$DOTEST"/current-commit ||
-		die "Cannot write current commit's replacement sha1"
-	fi
-
-	# rewrite parents; if none were rewritten, we can fast-forward.
-	fast_forward=t
-	preserve=t
-	new_parents=
-	for p in $(git rev-list --parents -1 $sha1 | cut -d' ' -f2-)
-	do
-		if test -f "$REWRITTEN"/$p
-		then
-			preserve=f
-			new_p=$(cat "$REWRITTEN"/$p)
-			test $p != $new_p && fast_forward=f
-			case "$new_parents" in
-			*$new_p*)
-				;; # do nothing; that parent is already there
-			*)
-				new_parents="$new_parents $new_p"
-				;;
-			esac
-		fi
-	done
-	case $fast_forward in
-	t)
-		output warn "Fast forward to $sha1"
-		test $preserve = f || echo $sha1 > "$REWRITTEN"/$sha1
-		;;
-	f)
-		test "a$1" = a-n && die "Refusing to squash a merge: $sha1"
-
-		first_parent=$(expr "$new_parents" : ' \([^ ]*\)')
-		# detach HEAD to current parent
-		output git checkout $first_parent 2> /dev/null ||
-			die "Cannot move HEAD to $first_parent"
-
-		echo $sha1 > "$DOTEST"/current-commit
-		case "$new_parents" in
-		' '*' '*)
-			# No point in merging the first parent, that's HEAD
-			redo_merge $sha1 ${new_parents# $first_parent}
-			;;
-		*)
-			output git cherry-pick "$@" ||
-				die_with_patch $sha1 "Could not pick $sha1"
-			;;
-		esac
-		;;
-	esac
-}
-
 nth_string () {
 	case "$1" in
 	*1[0-9]|*[04-9]) echo "$1"th;;
@@ -398,20 +334,7 @@ do_next () {
 	HEADNAME=$(cat "$DOTEST"/head-name) &&
 	OLDHEAD=$(cat "$DOTEST"/head) &&
 	SHORTONTO=$(git rev-parse --short $(cat "$DOTEST"/onto)) &&
-	if test -d "$REWRITTEN"
-	then
-		test -f "$DOTEST"/current-commit &&
-			current_commit=$(cat "$DOTEST"/current-commit) &&
-			git rev-parse HEAD > "$REWRITTEN"/$current_commit
-		if test -f "$REWRITTEN"/$OLDHEAD
-		then
-			NEWHEAD=$(cat "$REWRITTEN"/$OLDHEAD)
-		else
-			NEWHEAD=$OLDHEAD
-		fi
-	else
-		NEWHEAD=$(git rev-parse HEAD)
-	fi &&
+	NEWHEAD=$(git rev-parse HEAD) &&
 	case $HEADNAME in
 	refs/*)
 		message="$GIT_REFLOG_ACTION: $HEADNAME onto $SHORTONTO)" &&
@@ -436,6 +359,130 @@ do_rest () {
 	done
 }
 
+get_value_from_list () {
+	# args: "key" " key1#value1 key2#value2"
+	case "$2" in
+	*" $1#"*)
+		stm_tmp="${2#* $1#}"
+		echo "${stm_tmp%% *}"
+		unset stm_tmp
+		;;
+	*)
+		return 1
+		;;
+	esac
+}
+
+insert_value_at_key_into_list () {
+	# args: "value" "key" " key1#value1 key2#value2"
+	case "$3 " in
+	*" $2#$1 "*)
+		echo "$3"
+		;;
+	*" $2#"*)
+		echo "$3"
+		return 1
+		;;
+	*)
+		echo "$3 $2#$1"
+		;;
+	esac
+}
+
+create_extended_todo_list () {
+	(
+	while IFS=_ read commit parents subject
+	do
+		if test "${last_parent:-$commit}" != "$commit"
+		then
+			if test t = "${delayed_mark:-f}"
+			then
+				marked_commits=$(insert_value_at_key_into_list \
+					dummy $last_parent "${marked_commits:-}")
+				delayed_mark=f
+			fi
+			test "$last_parent" = $SHORTUPSTREAM && \
+				last_parent=$SHORTONTO
+			echo "reset $last_parent"
+		fi
+		last_parent="${parents%% *}"
+
+		get_value_from_list $commit "${marked_commits:-}" \
+			>/dev/null && echo mark
+
+		case "$parents" in
+		*' '*)
+			delayed_mark=t
+			new_parents=
+			for p in ${parents#* }
+			do
+				marked_commits=$(insert_value_at_key_into_list \
+					dummy "$p" "${marked_commits:-}")
+				if test "$p" = $SHORTUPSTREAM
+				then
+					new_parents="$new_parents $SHORTONTO"
+				else
+					new_parents="$new_parents $p"
+				fi
+			done
+			unset p
+			echo merge $commit $new_parents
+			unset new_parents
+			;;
+		*)
+			echo "pick $commit $subject"
+			;;
+		esac
+	done
+	test -n "${last_parent:-}" -a "${last_parent:-}" != $SHORTUPSTREAM && \
+		echo reset $last_parent
+	) | \
+	tac | \
+	while read cmd args
+	do
+		: ${commit_mark_list:=} ${last_commit:=000}
+		case "$cmd" in
+		pick)
+			last_commit="${args%% *}"
+			;;
+		mark)
+			: ${next_mark:=0}
+			if commit_mark_list=$(insert_value_at_key_into_list \
+				$next_mark $last_commit "$commit_mark_list")
+			then
+				args=":$next_mark"
+				next_mark=$(($next_mark + 1))
+			else
+				die "Internal error: two marks for" \
+					"the same commit"
+			fi
+			;;
+		reset)
+			if tmp=$(get_value_from_list $args "$commit_mark_list")
+			then
+				args=":$tmp"
+			fi
+			;;
+		merge)
+			new_args=
+			for i in ${args#* }
+			do
+				if tmp=$(get_value_from_list $i \
+					"$commit_mark_list")
+				then
+					new_args="$new_args :$tmp"
+				else
+					new_args="$new_args $i"
+				fi
+			done
+			last_commit="${args%% *}"
+			args="$last_commit ${new_args# }"
+			;;
+		esac
+		echo "$cmd $args"
+	done
+}
+
 while test $# != 0
 do
 	case "$1" in
@@ -568,33 +615,23 @@ do
 		echo $ONTO > "$DOTEST"/onto
 		test -z "$STRATEGY" || echo "$STRATEGY" > "$DOTEST"/strategy
 		test t = "$VERBOSE" && : > "$DOTEST"/verbose
-		if test t = "$PRESERVE_MERGES"
-		then
-			# $REWRITTEN contains files for each commit that is
-			# reachable by at least one merge base of $HEAD and
-			# $UPSTREAM. They are not necessarily rewritten, but
-			# their children might be.
-			# This ensures that commits on merged, but otherwise
-			# unrelated side branches are left alone. (Think "X"
-			# in the man page's example.)
-			mkdir "$REWRITTEN" &&
-			for c in $(git merge-base --all $HEAD $UPSTREAM)
-			do
-				echo $ONTO > "$REWRITTEN"/$c ||
-					die "Could not init rewritten commits"
-			done
-			MERGES_OPTION=
-		else
-			MERGES_OPTION=--no-merges
-		fi
 
 		SHORTUPSTREAM=$(git rev-parse --short=7 $UPSTREAM)
 		SHORTHEAD=$(git rev-parse --short=7 $HEAD)
 		SHORTONTO=$(git rev-parse --short=7 $ONTO)
-		git rev-list $MERGES_OPTION --pretty=oneline --abbrev-commit \
-			--abbrev=7 --reverse --left-right --cherry-pick \
-			$UPSTREAM...$HEAD | \
-			sed -n "s/^>/pick /p" > "$TODO"
+		common_rev_list_opts="--abbrev-commit --abbrev=7
+			--left-right --cherry-pick $UPSTREAM...$HEAD"
+		if test t = "$PRESERVE_MERGES"
+		then
+			git rev-list --pretty='format:%h_%p_%s' --topo-order \
+				$common_rev_list_opts | \
+				grep -v ^commit | \
+				create_extended_todo_list
+		else
+			git rev-list --no-merges --reverse --pretty=oneline \
+				 $common_rev_list_opts | sed -n "s/^>/pick /p"
+		fi > "$TODO"
+
 		cat >> "$TODO" << EOF
 
 # Rebase $SHORTUPSTREAM..$SHORTHEAD onto $SHORTONTO
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 0a8d065..f919aaf 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -258,7 +258,44 @@ test_expect_success 'preserve merges with -p' '
 	test $(git show HEAD~2:file1) = B
 '
 
+test_expect_success 'rebase with preserve merge forth and back is a noop' '
+	git checkout -b big-branch-1 master &&
+	test_tick &&
+	: > bb1a &&
+	git add bb1a &&
+	git commit -m "big branch commit 1" &&
+	: > bb1b &&
+	git add bb1b &&
+	git commit -m "big branch commit 2" &&
+	: > bb1c &&
+	git add bb1c &&
+	git commit -m "big branch commit 3" &&
+	git checkout -b big-branch-2 master &&
+	: > bb2a &&
+	git add bb2a &&
+	git commit -m "big branch commit 4" &&
+	: > bb2b &&
+	git add bb2b &&
+	git commit -m "big branch commit 5" &&
+	git merge big-branch-1~1 &&
+	git merge to-be-preserved &&
+	tbp_merge=$(git rev-parse HEAD) &&
+	: > bb2c &&
+	git add bb2c &&
+	git commit -m "big branch commit 6" &&
+	git merge big-branch-1 &&
+	head=$(git rev-parse HEAD) &&
+	FAKE_LINES="16 6 19 20 4 1 2 5 22" \
+		git rebase -i -p --onto dead-end master &&
+	test "$head" != "$(git rev-parse HEAD)" &&
+	FAKE_LINES="3 7 mark:10 8 9 5 1 2 merge$tbp_merge~1/:10 \
+		merge$tbp_merge/to-be-preserved 6 11" \
+		git rebase -i -p --onto master dead-end &&
+	test "$head" = "$(git rev-parse HEAD)"
+'
+
 test_expect_success '--continue tries to commit' '
+	git checkout to-be-rebased &&
 	test_tick &&
 	! git rebase -i --onto new-branch1 HEAD^ &&
 	echo resolved > file1 &&

Documentation/git-rebase.txt, git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index e0412e0..9ebbb90 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -11,7 +11,7 @@ SYNOPSIS
 'git-rebase' [-i | --interactive] [-v | --verbose] [-m | --merge]
 	[-s <strategy> | --strategy=<strategy>]
 	[-C<n>] [ --whitespace=<option>] [-p | --preserve-merges]
-	[--onto <newbase>] <upstream> [<branch>]
+	[-f | --first-parent] [--onto <newbase>] <upstream> [<branch>]
 'git-rebase' --continue | --skip | --abort
 
 DESCRIPTION
@@ -247,6 +247,11 @@ OPTIONS
 	Instead of ignoring merges, try to recreate them.  This option
 	only works in interactive mode.
 
+-f, \--first-parent::
+	This option implies the option --preserve-merges, but instead of
+	showing all commits from the merged branches show only the
+	commits and merges following the first parent of each commit.
+
 include::merge-strategies.txt[]
 
 NOTES
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index d3327a8..ea67942 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -10,8 +10,8 @@
 # The original idea comes from Eric W. Biederman, in
 # http://article.gmane.org/gmane.comp.version-control.git/22407
 
-USAGE='(--continue | --abort | --skip | [--preserve-merges] [--verbose]
-	[--onto <branch>] <upstream> [<branch>])'
+USAGE='(--continue | --abort | --skip | [--preserve-merges] [--first-parent]
+	[--verbose] [--onto <branch>] <upstream> [<branch>])'
 
 OPTIONS_SPEC=
 . git-sh-setup
@@ -565,6 +565,10 @@ do
 	-p|--preserve-merges)
 		PRESERVE_MERGES=t
 		;;
+	-f|--first-parent)
+		FIRST_PARENT=t
+		PRESERVE_MERGES=t
+		;;
 	-i|--interactive)
 		# yeah, we know
 		;;
@@ -621,10 +625,13 @@ do
 		SHORTONTO=$(git rev-parse --short=7 $ONTO)
 		common_rev_list_opts="--abbrev-commit --abbrev=7
 			--left-right --cherry-pick $UPSTREAM...$HEAD"
-		if test t = "$PRESERVE_MERGES"
+		if test t = "$PRESERVE_MERGES" -o t = "${FIRST_PARENT:-f}"
 		then
+			opts=
+			test t = "${FIRST_PARENT:-f}" && \
+				opts="$opts --first-parent"
 			git rev-list --pretty='format:%h_%p_%s' --topo-order \
-				$common_rev_list_opts | \
+				$opts $common_rev_list_opts | \
 				grep -v ^commit | \
 				create_extended_todo_list
 		else
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index f919aaf..8da7829 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -294,6 +294,18 @@ test_expect_success 'rebase with preserve merge forth and back is a noop' '
 	test "$head" = "$(git rev-parse HEAD)"
 '
 
+test_expect_success 'interactive --first-parent gives a linear list' '
+	head=$(git rev-parse HEAD) &&
+	EXPECT_COUNT=6 FAKE_LINES="2 1 4 3 6 5" \
+		git rebase -i -f --onto dead-end master &&
+	test "$head" != "$(git rev-parse HEAD)" &&
+	git rev-parse HEAD^^2 &&
+	test "$(git rev-parse HEAD~6)" = "$(git rev-parse dead-end)" &&
+	EXPECT_COUNT=6 FAKE_LINES="2 1 4 3 6 5" \
+		git rebase -i -f --onto master dead-end &&
+	test "$head" = "$(git rev-parse HEAD)"
+'
+
 test_expect_success '--continue tries to commit' '
 	git checkout to-be-rebased &&
 	test_tick &&

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index ea67942..c601655 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -323,6 +323,12 @@ do_next () {
 		mark_action_done
 		output git reset --hard $tmp
 		;;
+	tag|t)
+		comment_for_reflog tag
+
+		mark_action_done
+		output git tag -f "$sha1"
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		die_with_patch $sha1 "Please fix this in the file $TODO."
@@ -655,6 +661,7 @@ do
 #  reset commit = reset HEAD to the commit
 #  merge commit-M commit-P ... = redo merge commit-M with the
 #         current HEAD and the parents commit-P
+#  tag = reset tag to the current HEAD
 #
 # 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 8da7829..9901555 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -91,6 +91,9 @@ for line in $FAKE_LINES; do
 	merge*)
 		echo "merge ${line#merge}" | tr / ' '
 		echo "merge ${line#merge}" | tr / ' ' >> "$1";;
+	tag*)
+		echo "tag ${line#tag}"
+		echo "tag ${line#tag}" >> "$1";;
 	*)
 		sed -n "${line}{s/^pick/$action/; p;}" < "$1".tmp
 		sed -n "${line}{s/^pick/$action/; p;}" < "$1".tmp >> "$1"
@@ -306,6 +309,16 @@ test_expect_success 'interactive --first-parent gives a linear list' '
 	test "$head" = "$(git rev-parse HEAD)"
 '
 
+test_expect_success 'tag sets tags' '
+	head=$(git rev-parse HEAD) &&
+	FAKE_LINES="1 2 3 4 5 tagbb-tag1 6 7 8 9 10 11 12 13 14 15 \
+		tagbb-tag2 16 tagbb-tag3a tagbb-tag3b 17 18 19 20 21 22" \
+		EXPECT_COUNT=22 git rebase -i -p master &&
+	test "$head" = "$(git rev-parse HEAD)" &&
+	test "$(git rev-parse bb-tag1 bb-tag2 bb-tag3a bb-tag3b)" = \
+		"$(git rev-parse HEAD^2~2 HEAD~2 HEAD~1 HEAD~1)"
+'
+
 test_expect_success '--continue tries to commit' '
 	git checkout to-be-rebased &&
 	test_tick &&

Documentation/git-rebase.txt, git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/Documentation/git-rebase.txt b/Documentation/git-rebase.txt
index 9ebbb90..cc4e94f 100644
--- a/Documentation/git-rebase.txt
+++ b/Documentation/git-rebase.txt
@@ -11,7 +11,8 @@ SYNOPSIS
 'git-rebase' [-i | --interactive] [-v | --verbose] [-m | --merge]
 	[-s <strategy> | --strategy=<strategy>]
 	[-C<n>] [ --whitespace=<option>] [-p | --preserve-merges]
-	[-f | --first-parent] [--onto <newbase>] <upstream> [<branch>]
+	[-f | --first-parent] [-t | --preserve-tags]
+	[--onto <newbase>] <upstream> [<branch>]
 'git-rebase' --continue | --skip | --abort
 
 DESCRIPTION
@@ -252,6 +253,9 @@ OPTIONS
 	showing all commits from the merged branches show only the
 	commits and merges following the first parent of each commit.
 
+-t, \--preserve-tags::
+	If one of the commits has a tag, reset it to the new commit object.
+
 include::merge-strategies.txt[]
 
 NOTES
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index c601655..e874c31 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -11,7 +11,7 @@
 # http://article.gmane.org/gmane.comp.version-control.git/22407
 
 USAGE='(--continue | --abort | --skip | [--preserve-merges] [--first-parent]
-	[--verbose] [--onto <branch>] <upstream> [<branch>])'
+	[--preserve-tags] [--verbose] [--onto <branch>] <upstream> [<branch>])'
 
 OPTIONS_SPEC=
 . git-sh-setup
@@ -397,9 +397,31 @@ insert_value_at_key_into_list () {
 
 create_extended_todo_list () {
 	(
+	if test t = "${PRESERVE_TAGS:-}"
+	then
+		tag_list=$(git show-ref --abbrev=7 --tags | \
+			(
+			while read sha1 tag
+			do
+				tag=${tag#refs/tags/}
+				if test ${last_sha1:-0000} = $sha1
+				then
+					saved_tags="$saved_tags:$tag"
+				else
+					printf "%s" "${last_sha1:+ $last_sha1#$saved_tags}"
+					last_sha1=$sha1
+					saved_tags=$tag
+				fi
+			done
+			echo "${last_sha1:+ $last_sha1:$saved_tags}"
+			) )
+	else
+		tag_list=
+	fi
 	while IFS=_ read commit parents subject
 	do
-		if test "${last_parent:-$commit}" != "$commit"
+		if test t = "$PRESERVE_MERGES" -a \
+			"${last_parent:-$commit}" != "$commit"
 		then
 			if test t = "${delayed_mark:-f}"
 			then
@@ -416,6 +438,14 @@ create_extended_todo_list () {
 		get_value_from_list $commit "${marked_commits:-}" \
 			>/dev/null && echo mark
 
+		if tmp=$(get_value_from_list $commit "$tag_list")
+		then
+			for t in $(echo $tmp | tr : ' ')
+			do
+				echo tag $t
+			done
+		fi
+
 		case "$parents" in
 		*' '*)
 			delayed_mark=t
@@ -575,6 +605,9 @@ do
 		FIRST_PARENT=t
 		PRESERVE_MERGES=t
 		;;
+	-t|--preserve-tags)
+		PRESERVE_TAGS=t
+		;;
 	-i|--interactive)
 		# yeah, we know
 		;;
@@ -631,11 +664,14 @@ do
 		SHORTONTO=$(git rev-parse --short=7 $ONTO)
 		common_rev_list_opts="--abbrev-commit --abbrev=7
 			--left-right --cherry-pick $UPSTREAM...$HEAD"
-		if test t = "$PRESERVE_MERGES" -o t = "${FIRST_PARENT:-f}"
+		if test t = "$PRESERVE_MERGES" -o t = "${FIRST_PARENT:-f}" \
+			-o t = "${PRESERVE_TAGS:-}"
 		then
 			opts=
 			test t = "${FIRST_PARENT:-f}" && \
 				opts="$opts --first-parent"
+			test t != "$PRESERVE_MERGES" && \
+				opts="$opts --no-merges"
 			git rev-list --pretty='format:%h_%p_%s' --topo-order \
 				$opts $common_rev_list_opts | \
 				grep -v ^commit | \
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 9901555..d20ed4f 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -319,6 +319,16 @@ test_expect_success 'tag sets tags' '
 		"$(git rev-parse HEAD^2~2 HEAD~2 HEAD~1 HEAD~1)"
 '
 
+test_expect_success 'interactive -t preserves tags' '
+	git rebase -i -p -t --onto dead-end master &&
+	test "$(git rev-parse bb-tag1 bb-tag2 bb-tag3a bb-tag3b)" = \
+		"$(git rev-parse HEAD^2~2 HEAD~2 HEAD~1 HEAD~1)" &&
+	head=$(git rev-parse HEAD) &&
+	git rebase -i -t dead-end &&
+	test "$(git rev-parse bb-tag1 bb-tag2 bb-tag3a bb-tag3b)" = \
+		"$(git rev-parse HEAD~7 $head~2 HEAD~1 HEAD~1)"
+'
+
 test_expect_success '--continue tries to commit' '
 	git checkout to-be-rebased &&
 	test_tick &&

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 2a01182..2bd858c 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -493,6 +493,10 @@ create_extended_todo_list () {
 			if tmp=$(get_value_from_list $args "$commit_mark_list")
 			then
 				args=":$tmp"
+			elif tmp=$(git describe --all --exact-match $args \
+				2>/dev/null)
+			then
+				args="$tmp"
 			fi
 			;;
 		merge)
@@ -503,6 +507,10 @@ create_extended_todo_list () {
 					"$commit_mark_list")
 				then
 					new_args="$new_args :$tmp"
+				elif tmp=$(git describe --all --exact-match \
+					$i 2>/dev/null)
+				then
+					new_args="$new_args $tmp"
 				else
 					new_args="$new_args $i"
 				fi

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 531ee94..c0abc01 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -35,6 +35,8 @@ mark the corrected paths with 'git add <paths>', and
 run 'git rebase --continue'"
 export GIT_CHERRY_PICK_HELP
 
+mark_prefix=refs/rebase-marks/
+
 warn () {
 	echo "$*" >&2
 }
@@ -105,6 +107,10 @@ die_with_patch () {
 }
 
 cleanup_before_quit () {
+	for ref in $(git for-each-ref --format='%(refname)' "${mark_prefix%/}")
+	do
+		git update-ref -d "$ref" "$ref" || return 1
+	done
 	rm -rf "$DOTEST"
 }
 
@@ -244,6 +250,15 @@ peek_next_command () {
 	sed -n "1s/ .*$//p" < "$TODO"
 }
 
+mark_to_ref () {
+	if expr match "$1" "^:[0-9][0-9]*$" >/dev/null
+	then
+		echo "$mark_prefix$(printf %d ${1#:})"
+	else
+		echo "$1"
+	fi
+}
+
 do_next () {
 	rm -f "$DOTEST"/message "$DOTEST"/author-script \
 		"$DOTEST"/amend || exit
@@ -321,6 +336,17 @@ do_next () {
 			die_with_patch $sha1 ""
 		fi
 		;;
+	mark)
+		mark_action_done
+
+		mark=$(mark_to_ref :${sha1#:})
+		test :${sha1#:} = "$mark" && die "Invalid mark '$sha1'"
+
+		git rev-parse --verify "$mark" > /dev/null 2>&1 && \
+			warn "mark $sha1 already exist; overwriting it"
+
+		git update-ref "$mark" HEAD || die "update-ref failed"
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		die_with_patch $sha1 "Please fix this in the file $TODO."
@@ -533,10 +559,15 @@ do
 
 # Rebase $SHORTUPSTREAM..$SHORTHEAD onto $SHORTONTO
 #
+# In the todo insn whenever you need to refer to a commit, in addition
+# to the usual commit object name, you can use ':mark' syntax to refer
+# to a commit previously marked with the 'mark' insn.
+#
 # Commands:
 #  pick = use commit
 #  edit = use commit, but stop for amending
 #  squash = use commit, but meld into previous commit
+#  mark :mark = 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 8d29878..fa3560e 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 +192,20 @@ test_expect_success '-p handles "no changes" gracefully' '
 	test $HEAD = $(git rev-parse HEAD)
 '
 
+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/refs/rebase-marks &&
+	test -d $marks_dir &&
+	test $(ls $marks_dir | wc -l) -eq 2 &&
+	test "$(git rev-parse HEAD~4)" = \
+		"$(git rev-parse refs/rebase-marks/0)" &&
+	test "$(git rev-parse HEAD~2)" = \
+		"$(git rev-parse refs/rebase-marks/42)" &&
+	git rebase --abort &&
+	ls $marks_dir | wc -l | grep -Fx 0
+'
+
 test_expect_success 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&

git-rebase--interactive.sh, t/t3404-rebase-interactive.sh

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 531ee94..05d04da 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -35,6 +35,8 @@ mark the corrected paths with 'git add <paths>', and
 run 'git rebase --continue'"
 export GIT_CHERRY_PICK_HELP
 
+mark_prefix=refs/rebase-marks/
+
 warn () {
 	echo "$*" >&2
 }
@@ -105,7 +107,13 @@ die_with_patch () {
 }
 
 cleanup_before_quit () {
-	rm -rf "$DOTEST"
+	rm -rf "$DOTEST" &&
+	for ref in "$GIT_DIR/$mark_prefix"*
+	do
+		test "$ref" = "$GIT_DIR/$mark_prefix*" && continue
+		git update-ref -d "${ref#$GIT_DIR/}" "${ref#$GIT_DIR/}" || \
+			return 1
+	done
 }
 
 die_abort () {
@@ -244,6 +252,17 @@ peek_next_command () {
 	sed -n "1s/ .*$//p" < "$TODO"
 }
 
+mark_to_ref () {
+	case "$1" in
+	:[0-9]*)
+		echo "$mark_prefix$(printf %d ${1#:} 2>/dev/null)"
+		;;
+	*)
+		echo "$1"
+		;;
+	esac
+}
+
 do_next () {
 	rm -f "$DOTEST"/message "$DOTEST"/author-script \
 		"$DOTEST"/amend || exit
@@ -321,6 +340,15 @@ do_next () {
 			die_with_patch $sha1 ""
 		fi
 		;;
+	mark)
+		mark_action_done
+
+		mark=$(mark_to_ref :${sha1#:})
+		git rev-parse --verify "$mark" > /dev/null 2>&1 && \
+			warn "mark $sha1 already exist; overwriting it"
+
+		git update-ref "$mark" HEAD || die "update-ref failed"
+		;;
 	*)
 		warn "Unknown command: $command $sha1 $rest"
 		die_with_patch $sha1 "Please fix this in the file $TODO."
@@ -533,10 +561,15 @@ do
 
 # Rebase $SHORTUPSTREAM..$SHORTHEAD onto $SHORTONTO
 #
+# In the todo insn whenever you need to refer to a commit, in addition
+# to the usual commit object name, you can use ':mark' syntax to refer
+# to a commit previously marked with the 'mark' insn.
+#
 # Commands:
 #  pick = use commit
 #  edit = use commit, but stop for amending
 #  squash = use commit, but meld into previous commit
+#  mark :mark = 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 8d29878..fa3560e 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 +192,20 @@ test_expect_success '-p handles "no changes" gracefully' '
 	test $HEAD = $(git rev-parse HEAD)
 '
 
+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/refs/rebase-marks &&
+	test -d $marks_dir &&
+	test $(ls $marks_dir | wc -l) -eq 2 &&
+	test "$(git rev-parse HEAD~4)" = \
+		"$(git rev-parse refs/rebase-marks/0)" &&
+	test "$(git rev-parse HEAD~2)" = \
+		"$(git rev-parse refs/rebase-marks/42)" &&
+	git rebase --abort &&
+	ls $marks_dir | wc -l | grep -Fx 0
+'
+
 test_expect_success 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&

diff --git a/fast-import.c b/fast-import.c
index 73e5439..f60e4ab 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -1690,10 +1690,31 @@ static void skip_optional_lf(void)
 		ungetc(term_char, stdin);
 }
 
+static inline int parse_mark(const const char *str, uintmax_t* mark,
+	char **after_mark)
+{
+	if (!str || str[0] != ':' || !isdigit(str[1]))
+		return 1;
+
+	char *am;
+	const uintmax_t m = strtoumax(&str[1], &am, 10);
+	if (errno == 0) {
+		*mark = m;
+		*after_mark = am;
+		return 0;
+	}
+	return 1;
+}
+
 static void cmd_mark(void)
 {
-	if (!prefixcmp(command_buf.buf, "mark :")) {
-		next_mark = strtoumax(command_buf.buf + 6, NULL, 10);
+	uintmax_t mark = 0;
+	char *after_mark = NULL;
+
+	if (!prefixcmp(command_buf.buf, "mark ") &&
+		parse_mark(&command_buf.buf[5], &mark, &after_mark) &&
+		*after_mark == '\0') {
+		next_mark = mark;
 		read_next_command();
 	}
 	else
@@ -1878,7 +1899,10 @@ static void file_change_m(struct branch *b)
 
 	if (*p == ':') {
 		char *x;
-		oe = find_mark(strtoumax(p + 1, &x, 10));
+		uintmax_t m;
+		if (parse_mark(p, &m, &x))
+			die("Invalid mark: %s", p);
+		oe = find_mark(m);
 		hashcpy(sha1, oe->sha1);
 		p = x;
 	} else if (!prefixcmp(p, "inline")) {
@@ -2045,7 +2069,11 @@ static int cmd_from(struct branch *b)
 		hashcpy(b->branch_tree.versions[0].sha1, t);
 		hashcpy(b->branch_tree.versions[1].sha1, t);
 	} else if (*from == ':') {
-		uintmax_t idnum = strtoumax(from + 1, NULL, 10);
+		char *after_mark;
+		uintmax_t idnum;
+		if (parse_mark(from, &idnum, &after_mark) ||
+			*after_mark != '\0')
+			die("Not a valid mark: %s", from);
 		struct object_entry *oe = find_mark(idnum);
 		if (oe->type != OBJ_COMMIT)
 			die("Mark :%" PRIuMAX " not a commit", idnum);
@@ -2080,7 +2108,11 @@ static struct hash_list *cmd_merge(unsigned int *count)
 		if (s)
 			hashcpy(n->sha1, s->sha1);
 		else if (*from == ':') {
-			uintmax_t idnum = strtoumax(from + 1, NULL, 10);
+			char *after_mark;
+			uintmax_t idnum;
+			if (parse_mark(from, &idnum, &after_mark) ||
+				*after_mark != '\0')
+				die("Not a valid mark: %s", from);
 			struct object_entry *oe = find_mark(idnum);
 			if (oe->type != OBJ_COMMIT)
 				die("Mark :%" PRIuMAX " not a commit", idnum);
@@ -2228,7 +2260,10 @@ static void cmd_new_tag(void)
 		hashcpy(sha1, s->sha1);
 	} else if (*from == ':') {
 		struct object_entry *oe;
-		from_mark = strtoumax(from + 1, NULL, 10);
+		char *after_mark;
+		if (parse_mark(from, &from_mark, &after_mark) ||
+			*after_mark != '\0')
+			die("Not a valid mark: %s", from);
 		oe = find_mark(from_mark);
 		if (oe->type != OBJ_COMMIT)
 			die("Mark :%" PRIuMAX " not a commit", from_mark);
@@ -2333,9 +2368,8 @@ static void import_marks(const char *input_file)
 		if (line[0] != ':' || !end)
 			die("corrupt mark line: %s", line);
 		*end = 0;
-		mark = strtoumax(line + 1, &end, 10);
-		if (!mark || end == line + 1
-			|| *end != ' ' || get_sha1(end + 1, sha1))
+		if (parse_mark(line, &mark, &end) || !mark ||
+			*end != ' ' || get_sha1(end + 1, sha1))
 			die("corrupt mark line: %s", line);
 		e = find_object(sha1);
 		if (!e) {

Bye, Jörg.

diff --git a/fast-import.c b/fast-import.c
index 73e5439..0c71da8 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -1690,12 +1690,31 @@ static void skip_optional_lf(void)
 		ungetc(term_char, stdin);
 }
 
+static inline uintmax_t parse_mark(const const char *str, char **after_mark)
+{
+	char *am;
+	uintmax_t m;
+
+	if (!str || str[0] != ':' || !isdigit(str[1]))
+		return 0;
+
+	m = strtoumax(&str[1], &am, 10);
+	if (m != UINTMAX_MAX || errno == 0) {
+		*after_mark = am;
+		return m;
+	}
+	return 0;
+}
+
 static void cmd_mark(void)
 {
-	if (!prefixcmp(command_buf.buf, "mark :")) {
-		next_mark = strtoumax(command_buf.buf + 6, NULL, 10);
+	uintmax_t mark;
+	char *after_mark = NULL;
+
+	if (!prefixcmp(command_buf.buf, "mark ") &&
+		(next_mark = parse_mark(&command_buf.buf[5], &after_mark)) &&
+		*after_mark == '\0')
 		read_next_command();
-	}
 	else
 		next_mark = 0;
 }
@@ -1877,8 +1896,8 @@ static void file_change_m(struct branch *b)
 	}
 
 	if (*p == ':') {
-		char *x;
-		oe = find_mark(strtoumax(p + 1, &x, 10));
+		char *x = NULL;
+		oe = find_mark(parse_mark(p, &x));
 		hashcpy(sha1, oe->sha1);
 		p = x;
 	} else if (!prefixcmp(p, "inline")) {
@@ -2045,7 +2064,10 @@ static int cmd_from(struct branch *b)
 		hashcpy(b->branch_tree.versions[0].sha1, t);
 		hashcpy(b->branch_tree.versions[1].sha1, t);
 	} else if (*from == ':') {
-		uintmax_t idnum = strtoumax(from + 1, NULL, 10);
+		char *after_mark;
+		uintmax_t idnum = parse_mark(from, &after_mark);
+		if (!idnum || *after_mark != '\0')
+			die("Not a valid mark: %s", from);
 		struct object_entry *oe = find_mark(idnum);
 		if (oe->type != OBJ_COMMIT)
 			die("Mark :%" PRIuMAX " not a commit", idnum);
@@ -2080,7 +2102,10 @@ static struct hash_list *cmd_merge(unsigned int *count)
 		if (s)
 			hashcpy(n->sha1, s->sha1);
 		else if (*from == ':') {
-			uintmax_t idnum = strtoumax(from + 1, NULL, 10);
+			char *after_mark;
+			uintmax_t idnum = parse_mark(from, &after_mark);
+			if (!idnum || *after_mark != '\0')
+				die("Not a valid mark: %s", from);
 			struct object_entry *oe = find_mark(idnum);
 			if (oe->type != OBJ_COMMIT)
 				die("Mark :%" PRIuMAX " not a commit", idnum);
@@ -2228,7 +2253,10 @@ static void cmd_new_tag(void)
 		hashcpy(sha1, s->sha1);
 	} else if (*from == ':') {
 		struct object_entry *oe;
-		from_mark = strtoumax(from + 1, NULL, 10);
+		char *after_mark;
+		from_mark = parse_mark(from, &after_mark);
+		if (!from_mark || *after_mark != '\0')
+			die("Not a valid mark: %s", from);
 		oe = find_mark(from_mark);
 		if (oe->type != OBJ_COMMIT)
 			die("Mark :%" PRIuMAX " not a commit", from_mark);
@@ -2333,9 +2361,8 @@ static void import_marks(const char *input_file)
 		if (line[0] != ':' || !end)
 			die("corrupt mark line: %s", line);
 		*end = 0;
-		mark = strtoumax(line + 1, &end, 10);
-		if (!mark || end == line + 1
-			|| *end != ' ' || get_sha1(end + 1, sha1))
+		mark = parse_mark(line, &end);
+		if (!mark || *end != ' ' || get_sha1(end + 1, sha1))
 			die("corrupt mark line: %s", line);
 		e = find_object(sha1);
 		if (!e) {