Merge branch 'pw/mailinfo-b-fix'

Fix a logic in "mailinfo -b" that miscomputed the length of a
substring, which lead to an out-of-bounds access.

* pw/mailinfo-b-fix:
  mailinfo -b: fix an out of bounds access

Author: gitster

mailinfo.c

@@ -317,7 +317,7 @@ static void cleanup_subject(struct mailinfo *mi, struct strbuf *subject)
 			pos = strchr(subject->buf + at, ']');
 			if (!pos)
 				break;
-			remove = pos - subject->buf + at + 1;
+			remove = pos - (subject->buf + at) + 1;
 			if (!mi->keep_non_patch_brackets_in_subject ||
 			    (7 <= remove &&
 			     memmem(subject->buf + at, remove, "PATCH", 5)))

t/t5100-mailinfo.sh

@@ -201,13 +201,13 @@ test_expect_success 'mailinfo -b double [PATCH]' '
 	test z"$subj" = z"Subject: message"
 '
 
-test_expect_failure 'mailinfo -b trailing [PATCH]' '
+test_expect_success 'mailinfo -b trailing [PATCH]' '
 	subj="$(echo "Subject: [other] [PATCH] message" |
 		git mailinfo -b /dev/null /dev/null)" &&
 	test z"$subj" = z"Subject: [other] message"
 '
 
-test_expect_failure 'mailinfo -b separated double [PATCH]' '
+test_expect_success 'mailinfo -b separated double [PATCH]' '
 	subj="$(echo "Subject: [PATCH] [other] [PATCH] message" |
 		git mailinfo -b /dev/null /dev/null)" &&
 	test z"$subj" = z"Subject: [other] message"