Merge branch 'js/rebase-i-clean-up-upon-continue-to-skip' into maint

Abandoning an already applied change in "git rebase -i" with
"--continue" left CHERRY_PICK_HEAD and confused later steps.

* js/rebase-i-clean-up-upon-continue-to-skip:
  rebase -i: do not leave a CHERRY_PICK_HEAD file behind
  t3404: demonstrate CHERRY_PICK_HEAD bug

Author: gitster

git-rebase--interactive.sh

@@ -849,7 +849,11 @@ continue)
 	# do we have anything to commit?
 	if git diff-index --cached --quiet HEAD --
 	then
-		: Nothing to commit -- skip this
+		# Nothing to commit -- skip this commit
+
+		test ! -f "$GIT_DIR"/CHERRY_PICK_HEAD ||
+		rm "$GIT_DIR"/CHERRY_PICK_HEAD ||
+		die "Could not remove CHERRY_PICK_HEAD"
 	else
 		if ! test -f "$author_script"
 		then

t/t3404-rebase-interactive.sh

@@ -1102,4 +1102,25 @@ test_expect_success 'rebase -i commits that overwrite untracked files (no ff)' '
 	test $(git cat-file commit HEAD | sed -ne \$p) = I
 '
 
+test_expect_success 'rebase --continue removes CHERRY_PICK_HEAD' '
+	git checkout -b commit-to-skip &&
+	for double in X 3 1
+	do
+		test_seq 5 | sed "s/$double/&&/" >seq &&
+		git add seq &&
+		test_tick &&
+		git commit -m seq-$double
+	done &&
+	git tag seq-onto &&
+	git reset --hard HEAD~2 &&
+	git cherry-pick seq-onto &&
+	set_fake_editor &&
+	test_must_fail env FAKE_LINES= git rebase -i seq-onto &&
+	test -d .git/rebase-merge &&
+	git rebase --continue &&
+	git diff --exit-code seq-onto &&
+	test ! -d .git/rebase-merge &&
+	test ! -f .git/CHERRY_PICK_HEAD
+'
+
 test_done