fetch: die on invalid --negotiation-tip hash

If a full hexadecimal hash is given as a --negotiation-tip to "git
fetch", and that hash does not correspond to an object, "git fetch" will
segfault if --negotiate-only is given and will silently ignore that hash
otherwise. Make these cases fatal errors, just like the case when an
invalid ref name or abbreviated hash is given.

While at it, mark the error messages as translatable.

Signed-off-by: Jonathan Tan <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: jonathantanmy

builtin/fetch.c

@@ -1428,7 +1428,9 @@ static void add_negotiation_tips(struct git_transport_options *smart_options)
 		if (!has_glob_specials(s)) {
 			struct object_id oid;
 			if (get_oid(s, &oid))
-				die("%s is not a valid object", s);
+				die(_("%s is not a valid object"), s);
+			if (!has_object(the_repository, &oid, 0))
+				die(_("the object %s does not exist"), s);
 			oid_array_append(oids, &oid);
 			continue;
 		}

t/t5510-fetch.sh

@@ -1214,6 +1214,19 @@ test_expect_success '--negotiation-tip understands abbreviated SHA-1' '
 	check_negotiation_tip
 '
 
+test_expect_success '--negotiation-tip rejects missing OIDs' '
+	setup_negotiation_tip server server 0 &&
+	test_must_fail git -C client fetch \
+		--negotiation-tip=alpha_1 \
+		--negotiation-tip=$(test_oid zero) \
+		origin alpha_s beta_s 2>err &&
+	cat >fatal-expect <<-EOF &&
+	fatal: the object $(test_oid zero) does not exist
+EOF
+	grep fatal: err >fatal-actual &&
+	test_cmp fatal-expect fatal-actual
+'
+
 . "$TEST_DIRECTORY"/lib-httpd.sh
 start_httpd