show-ref: use die_for_incompatible_opt3()

Use the standard message for reporting the use of multiple mutually
exclusive options by calling die_for_incompatible_opt3() instead of
rolling our own.  This has the benefits of showing only the actually
given options, reducing the number of strings to translate and making
the UI slightly more consistent.

Adjust the test to no longer insist on a specific order of the
reported options, as this implementation detail does not affect the
usefulness of the error message.

Reported-by: Eric Sunshine <[email protected]>
Signed-off-by: René Scharfe <[email protected]>
Reviewed-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

builtin/show-ref.c

@@ -315,9 +315,9 @@ int cmd_show_ref(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, show_ref_options,
 			     show_ref_usage, 0);
 
-	if ((!!exclude_existing_opts.enabled + !!verify + !!exists) > 1)
-		die(_("only one of '%s', '%s' or '%s' can be given"),
-		    "--exclude-existing", "--verify", "--exists");
+	die_for_incompatible_opt3(exclude_existing_opts.enabled, "--exclude-existing",
+				  verify, "--verify",
+				  exists, "--exists");
 
 	if (exclude_existing_opts.enabled)
 		return cmd_show_ref__exclude_existing(&exclude_existing_opts);

t/t1403-show-ref.sh

@@ -197,18 +197,20 @@ test_expect_success 'show-ref --verify with dangling ref' '
 '
 
 test_expect_success 'show-ref sub-modes are mutually exclusive' '
-	cat >expect <<-EOF &&
-	fatal: only one of ${SQ}--exclude-existing${SQ}, ${SQ}--verify${SQ} or ${SQ}--exists${SQ} can be given
-	EOF
-
 	test_must_fail git show-ref --verify --exclude-existing 2>err &&
-	test_cmp expect err &&
+	grep "verify" err &&
+	grep "exclude-existing" err &&
+	grep "cannot be used together" err &&
 
 	test_must_fail git show-ref --verify --exists 2>err &&
-	test_cmp expect err &&
+	grep "verify" err &&
+	grep "exists" err &&
+	grep "cannot be used together" err &&
 
 	test_must_fail git show-ref --exclude-existing --exists 2>err &&
-	test_cmp expect err
+	grep "exclude-existing" err &&
+	grep "exists" err &&
+	grep "cannot be used together" err
 '
 
 test_expect_success '--exists with existing reference' '