bisect: libify `handle_bad_merge_base` and its dependents

Since we want to get rid of git-bisect.sh, it would be necessary to
convert those exit() calls to return statements so that errors can be
reported.

Emulate try catch in C by converting `exit(<positive-value>)` to
`return <negative-value>`. Follow POSIX conventions to return
<negative-value> to indicate error.

Update all callers to handle the error returns.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Tanushree Tumane <tanushreetumane@gmail.com>
Signed-off-by: Miriam Rubio <mirucam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/bisect.c b/bisect.c
index f5ce3a4b70d536f4d3cc0ab93c914a7172f03787..837332a428161841dfae544b2b34aa9803283a00 100644 (file)
--- a/bisect.c
+++ b/bisect.c
@@ -761,7 +761,7 @@ static struct commit **get_bad_and_good_commits(struct repository *r,
        return rev;
 }
 
-static void handle_bad_merge_base(void)
+static enum bisect_error handle_bad_merge_base(void)
 {
        if (is_expected_rev(current_bad_oid)) {
                char *bad_hex = oid_to_hex(current_bad_oid);
@@ -782,14 +782,14 @@ static void handle_bad_merge_base(void)
                                "between %s and [%s].\n"),
                                bad_hex, term_bad, term_good, bad_hex, good_hex);
                }
-               exit(3);
+               return BISECT_MERGE_BASE_CHECK;
        }
 
        fprintf(stderr, _("Some %s revs are not ancestors of the %s rev.\n"
                "git bisect cannot work properly in this case.\n"
                "Maybe you mistook %s and %s revs?\n"),
                term_good, term_bad, term_good, term_bad);
-       exit(1);
+       return BISECT_FAILED;
 }
 
 static void handle_skipped_merge_base(const struct object_id *mb)
@@ -830,7 +830,8 @@ static enum bisect_error check_merge_bases(int rev_nr, struct commit **rev, int
        for (; result; result = result->next) {
                const struct object_id *mb = &result->item->object.oid;
                if (oideq(mb, current_bad_oid)) {
-                       handle_bad_merge_base();
+                       res = handle_bad_merge_base();
+                       break;
                } else if (0 <= oid_array_lookup(&good_revs, mb)) {
                        continue;
                } else if (0 <= oid_array_lookup(&skipped_revs, mb)) {

diff --git a/bisect.h b/bisect.h
index f68ae853766b1f11233d82df7e89f9abd79bfc55..0d9758179f1a6eb85fb1276d506bc77a6b192e97 100644 (file)
--- a/bisect.h
+++ b/bisect.h
@@ -48,6 +48,7 @@ enum bisect_error {
        BISECT_OK = 0,
        BISECT_FAILED = -1,
        BISECT_ONLY_SKIPPED_LEFT = -2,
+       BISECT_MERGE_BASE_CHECK = -3,
        BISECT_INTERNAL_SUCCESS_MERGE_BASE = -11
 };