bisect--helper: `bisect_clean_state` shell function in C

Reimplement `bisect_clean_state` shell function in C and add a
`bisect-clean-state` subcommand to `git bisect--helper` to call it from
git-bisect.sh .

Using `--bisect-clean-state` subcommand is a measure to port shell
function to C so as to use the existing test suite. As more functions
are ported, this subcommand will be retired but its implementation  will
be called by bisect_reset() and bisect_start().

Also introduce a function `mark_for_removal` to store the refs which
need to be removed while iterating through the refs.

Mentored-by: Lars Schneider <larsxschneider@gmail.com>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 3 insertions, 23 deletions

diff --git a/git-bisect.sh b/git-bisect.sh
index a80fc44e5..045830c39 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -186,7 +186,7 @@ bisect_start() {
 	#
 	# Get rid of any old bisect state.
 	#
-	bisect_clean_state || exit
+	git bisect--helper --bisect-clean-state || exit
 
 	#
 	# Change state.
@@ -195,7 +195,7 @@ bisect_start() {
 	# We have to trap this to be able to clean up using
 	# "bisect_clean_state".
 	#
-	trap 'bisect_clean_state' 0
+	trap 'git bisect--helper --bisect-clean-state' 0
 	trap 'exit 255' 1 2 3 15
 
 	#
@@ -430,27 +430,7 @@ bisect_reset() {
 		die "$(eval_gettext "Could not check out original HEAD '\$branch'.
 Try 'git bisect reset <commit>'.")"
 	fi
-	bisect_clean_state
-}
-
-bisect_clean_state() {
-	# There may be some refs packed during bisection.
-	git for-each-ref --format='%(refname) %(objectname)' refs/bisect/\* |
-	while read ref hash
-	do
-		git update-ref -d $ref $hash || exit
-	done
-	rm -f "$GIT_DIR/BISECT_EXPECTED_REV" &&
-	rm -f "$GIT_DIR/BISECT_ANCESTORS_OK" &&
-	rm -f "$GIT_DIR/BISECT_LOG" &&
-	rm -f "$GIT_DIR/BISECT_NAMES" &&
-	rm -f "$GIT_DIR/BISECT_RUN" &&
-	rm -f "$GIT_DIR/BISECT_TERMS" &&
-	# Cleanup head-name if it got left by an old version of git-bisect
-	rm -f "$GIT_DIR/head-name" &&
-	git update-ref -d --no-deref BISECT_HEAD &&
-	# clean up BISECT_START last
-	rm -f "$GIT_DIR/BISECT_START"
+	git bisect--helper --bisect-clean-state || exit
 }
 
 bisect_replay () {