[PATCH] rebase -i: avoid 'git reset' when possible

From

Johannes Schindelin <johannes.schindelin@gmx.de>

Date

Feb 27, 2009, 12:56 UTC

Message-ID

<alpine.DEB.1.00.0902271354130.6600@intel-tinevez-2-302>

In-Reply-To

<alpine.DEB.1.00.0902271146460.6600@intel-tinevez-2-302>

Requested by Sverre Rabbelier.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---

	On Fri, 27 Feb 2009, Johannes Schindelin wrote:

	> Having said that, I think yours might be such a common case that
	> it is worth optimizing for.

	And so I did.

 git-rebase--interactive.sh    |   23 +++++++++++++++++++++++
 t/t3404-rebase-interactive.sh |   11 +++++++++++
 2 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 3dc659d..a9617a2 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -442,6 +442,27 @@ do_rest () {
 	done
 }
 
+# skip picking commits whose parents are unchanged
+skip_unnecessary_picks () {
+	current=$ONTO
+	i=0
+	while read command sha1 rest
+	do
+		test pick = "$command" &&
+		test $current = "$(git rev-parse $sha1^)" ||
+		break
+		current=$(git rev-parse $sha1)
+		i=$(($i+1))
+	done < "$TODO"
+	test $i = 0 || {
+		sed -e "${i}q" < "$TODO" >> "$DONE" &&
+		sed -e "1,${i}d" < "$TODO" >> "$TODO".new &&
+		mv -f "$TODO".new "$TODO" &&
+		ONTO=$current ||
+		die "Could not skip $i pick commands"
+	}
+}
+
 # check if no other options are set
 is_standalone () {
 	test $# -eq 2 -a "$2" = '--' &&
@@ -746,6 +767,8 @@ EOF
 		has_action "$TODO" ||
 			die_abort "Nothing to do"
 
+		test -d "$REWRITTEN" || skip_unnecessary_picks
+
 		git update-ref ORIG_HEAD $HEAD
 		output git checkout $ONTO && do_rest
 		;;
diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
index 603b003..c32ff66 100755
--- a/t/t3404-rebase-interactive.sh
+++ b/t/t3404-rebase-interactive.sh
@@ -459,4 +459,15 @@ test_expect_success 'submodule rebase -i' '
 	FAKE_LINES="1 squash 2 3" git rebase -i A
 '
 
+test_expect_success 'avoid unnecessary reset' '
+	git checkout master &&
+	test-chmtime =123456789 file3 &&
+	git update-index --refresh &&
+	HEAD=$(git rev-parse HEAD) &&
+	git rebase -i HEAD~4 &&
+	test $HEAD = $(git rev-parse HEAD) &&
+	MTIME=$(test-chmtime -v +0 file3 | sed 's/[^0-9].*$//') &&
+	test 123456789 = $MTIME
+'
+
 test_done

-- 
1.6.2.rc1.350.g6caf6