[PATCH v2] rebase -i: avoid 'git reset' when possible
When picking commits whose parents have not changed, we do not need to rewrite the commit. We do not need to reset the working directory to the parent's state, either.
Requested by Sverre Rabbelier.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
Actually, I did not think things through. Of _course_ we need
that rev-parse, to determine the parent of the to-be-picked
commit.
Changes since v1: use only one loop instead of counting the number
of skipped commits first, and then actually skipping them.
git-rebase--interactive.sh | 26 ++++++++++++++++++++++++++
t/t3404-rebase-interactive.sh | 11 +++++++++++
2 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 3dc659d..72f7fc7 100755
--- a/git-rebase--interactive.sh
+++ b/git-rebase--interactive.sh
@@ -442,6 +442,30 @@ do_rest () {
done
}
+# skip picking commits whose parents are unchanged
+skip_unnecessary_picks () {
+ fd=3
+ while read command sha1 rest
+ do
+ # fd=3 means we skip the command
+ case "$fd,$command,$(git rev-parse --verify --quiet $sha1^)" in
+ 3,pick,"$ONTO"*|t,p,"$ONTO"*)
+ # pick a commit whose parent is current $ONTO -> skip
+ ONTO=$sha1
+ ;;
+ 3,#*|3,,*)
+ # copy comments
+ ;;
+ *)
+ fd=1
+ ;;
+ esac
+ echo "$command${sha1:+ }$sha1${rest:+ }$rest" >&$fd
+ done < "$TODO" > "$TODO.new" 3>> "$DONE" &&
+ mv -f "$TODO".new "$TODO" ||
+ die "Could not skip unnecessary pick commands"
+}
+
# check if no other options are set
is_standalone () {
test $# -eq 2 -a "$2" = '--' &&
@@ -746,6 +770,8 @@ EOF
has_action "$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.rc1.456.g3dbe7
Sverre Rabbelier
