Merge branch 'js/rebase-i-opt'

* js/rebase-i-opt:
rebase -i: avoid 'git reset' when possible

diff --git a/git-rebase--interactive.sh b/git-rebase--interactive.sh
index 3dc659dd5896ce6c887eb786718919aef82f4ac6..314cd364b8f4df5e170dd0ffd9e874b3e6c2737c 100755 (executable)
--- 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"*|3,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 603b003edff6d32fe8725f119778658c76c806fb..c32ff6682b932b3d9b270de7260a2671d8d07403 100755 (executable)
--- 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