Subject: [PATCH 11/26] bisect--helper: Finish `bisect_start()` conversion

From: "Pranit Bauva via GitGitGadget" <[email-masked]>
Date: Sun, 24 Feb 2019 02:11:23 -0800 (PST)

From: Pranit Bauva <[email-masked]>

With the conversion of `bisect_auto_next()` in previous commit,
`bisect_start()` has been successfully ported to C.

Add the subcommands to `git bisect--helper` and call it from
git-bisect.sh.

Remove `bisect_start()` shell method and call `git bisect--helper --bisect-start` subcommand
from git-bisect.sh.

Removing the part about signals as we are not doing anything
anymore to trap signals. While at it, "trap" is changed to
"handle". As "trap" is a reference to the shell "trap" builtin,
which isn't used anymore.

Mentored-by: Christian Couder <[email-masked]>
Mentored-by: Johannes Schindelin <[email-masked]>
Signed-off-by: Pranit Bauva <[email-masked]>
Signed-off-by: Tanushree Tumane <[email-masked]>
---
 builtin/bisect--helper.c | 29 +++++++++++++++++++++++++++--
 git-bisect.sh            | 29 +++--------------------------
 2 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/builtin/bisect--helper.c b/builtin/bisect--helper.c
index 2f19924471..d538cb04fb 100644
--- a/builtin/bisect--helper.c
+++ b/builtin/bisect--helper.c
@@ -697,9 +697,9 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 		return -1;
 
 	/*
-	 * In case of mistaken revs or checkout error, or signals received,
+	 * In case of mistaken revs or checkout error,
 	 * "bisect_auto_next" below may exit or misbehave.
-	 * We have to trap this to be able to clean up using
+	 * We have to handle this to be able to clean up using
 	 * "bisect_clean_state".
 	 */
 
@@ -743,6 +743,31 @@ static int bisect_start(struct bisect_terms *terms, int no_checkout,
 	string_list_clear(&states, 0);
 	strbuf_release(&start_head);
 	strbuf_release(&bisect_names);
+	if (res)
+		return res;
+
+	res = bisect_auto_next(terms, NULL);
+	/*
+	 * In case of mistaken revs or checkout error, or signals received,
+	 * "bisect_auto_next" below may exit or misbehave.
+	 * We have to trap this to be able to clean up using
+	 * "bisect_clean_state".
+	 * return code -11 is special code that indicates special success.
+	 *	-> bisect_start()
+	 *	   . res = bisect_auto_next()
+	 *	    -> bisect_auto_next()
+	 *	       . return bisect_next()
+	 *	       -> bisect_next()
+	 *		  . res = bisect_next_all()
+	 *		  -> bisect_next_all()
+	 *		     . res = check_good_are_ancestors_of_bad()
+	 *		     -> check_good_are_ancestors_of_bad()
+	 *			. res = check_merge_bases()
+	 *			-> check_merge_bases()
+	 *			   . res = -11
+	 */
+	if (res && res != -11)
+		bisect_clean_state();
 	return res;
 }
 
diff --git a/git-bisect.sh b/git-bisect.sh
index 7531b74708..fec527e1ef 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -63,35 +63,13 @@ bisect_autostart() {
 			[Nn]*)
 				exit ;;
 			esac
-			bisect_start
+			git bisect--helper --bisect-start
 		else
 			exit 1
 		fi
 	}
 }
 
-bisect_start() {
-	git bisect--helper --bisect-start $@ || exit
-
-	#
-	# Change state.
-	# In case of mistaken revs or checkout error, or signals received,
-	# "bisect_auto_next" below may exit or misbehave.
-	# We have to trap this to be able to clean up using
-	# "bisect_clean_state".
-	#
-	trap 'git bisect--helper --bisect-clean-state' 0
-	trap 'exit 255' 1 2 3 15
-
-	#
-	# Check if we can proceed to the next bisect state.
-	#
-	get_terms
-	git bisect--helper --bisect-auto-next || exit
-
-	trap '-' 0
-}
-
 bisect_skip() {
 	all=''
 	for arg in "$@"
@@ -184,8 +162,7 @@ bisect_replay () {
 		get_terms
 		case "$command" in
 		start)
-			cmd="bisect_start $rev"
-			eval "$cmd" ;;
+			eval "git bisect--helper --bisect-start $rev" ;;
 		"$TERM_GOOD"|"$TERM_BAD"|skip)
 			git bisect--helper --bisect-write "$command" "$rev" "$TERM_GOOD" "$TERM_BAD" || exit;;
 		terms)
@@ -284,7 +261,7 @@ case "$#" in
 	help)
 		git bisect -h ;;
 	start)
-		bisect_start "$@" ;;
+		git bisect--helper --bisect-start "$@" ;;
 	bad|good|new|old|"$TERM_BAD"|"$TERM_GOOD")
 		bisect_state "$cmd" "$@" ;;
 	skip)
-- 
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