mktag: add a --[no-]strict option

Now that mktag has been migrated to use the fsck machinery to check
its input, it makes sense to teach it to run in the equivalent of "git
fsck"'s default mode.

For cases where mktag is used to (re)create a tag object using data
from an existing and malformed tag object, the validation may
optionally have to be loosened. Teach the command to take the
"--[no-]strict" option to do so.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-mktag.txt

@@ -11,6 +11,14 @@ SYNOPSIS
 [verse]
 'git mktag'
 
+OPTIONS
+-------
+
+--strict::
+	By default mktag turns on the equivalent of
+	linkgit:git-fsck[1] `--strict` mode. Use `--no-strict` to
+	disable it.
+
 DESCRIPTION
 -----------
 

builtin/mktag.c

@@ -10,6 +10,7 @@ static char const * const builtin_mktag_usage[] = {
 	N_("git mktag"),
 	NULL
 };
+static int option_strict = 1;
 
 static struct fsck_options fsck_options = FSCK_OPTIONS_STRICT;
 
@@ -25,6 +26,12 @@ static int mktag_fsck_error_func(struct fsck_options *o,
 {
 	switch (msg_type) {
 	case FSCK_WARN:
+		if (!option_strict) {
+			fprintf_ln(stderr, _("warning: tag input does not pass fsck: %s"), message);
+			return 0;
+
+		}
+		/* fallthrough */
 	case FSCK_ERROR:
 		/*
 		 * We treat both warnings and errors as errors, things
@@ -67,6 +74,8 @@ static int verify_object_in_tag(struct object_id *tagged_oid, int *tagged_type)
 int cmd_mktag(int argc, const char **argv, const char *prefix)
 {
 	static struct option builtin_mktag_options[] = {
+		OPT_BOOL(0, "strict", &option_strict,
+			 N_("enable more strict checking")),
 		OPT_END(),
 	};
 	struct strbuf buf = STRBUF_INIT;

t/t3800-mktag.sh

@@ -12,12 +12,17 @@ test_description='git mktag: tag object verify test'
 # given in the expect.pat file.
 
 check_verify_failure () {
-	expect="$2"
-	test_expect_success "$1" '
+	test_expect_success "$1" "
 		test_must_fail env GIT_TEST_GETTEXT_POISON=false \
 			git mktag <tag.sig 2>message &&
-		grep "$expect" message
-	'
+		grep '$2' message &&
+		if test '$3' != '--no-strict'
+		then
+			test_must_fail env GIT_TEST_GETTEXT_POISON=false \
+				git mktag --no-strict <tag.sig 2>message.no-strict &&
+			grep '$2' message.no-strict
+		fi
+	"
 }
 
 test_expect_mktag_success() {
@@ -65,7 +70,7 @@ too short for a tag
 EOF
 
 check_verify_failure 'Tag object length check' \
-	'^error:.* missingObject:'
+	'^error:.* missingObject:' 'strict'
 
 ############################################################
 #  2. object line label check
@@ -240,7 +245,7 @@ tagger . <> 0 +0000
 EOF
 
 check_verify_failure 'verify tag-name check' \
-	'^error:.* badTagName:'
+	'^error:.* badTagName:' '--no-strict'
 
 ############################################################
 # 11. tagger line label check #1
@@ -254,7 +259,7 @@ This is filler
 EOF
 
 check_verify_failure '"tagger" line label check #1' \
-	'^error:.* missingTaggerEntry:'
+	'^error:.* missingTaggerEntry:' '--no-strict'
 
 ############################################################
 # 12. tagger line label check #2
@@ -269,7 +274,7 @@ This is filler
 EOF
 
 check_verify_failure '"tagger" line label check #2' \
-	'^error:.* missingTaggerEntry:'
+	'^error:.* missingTaggerEntry:' '--no-strict'
 
 ############################################################
 # 13. allow missing tag author name like fsck
@@ -298,7 +303,7 @@ tagger T A Gger <
 EOF
 
 check_verify_failure 'disallow malformed tagger' \
-	'^error:.* badEmail:'
+	'^error:.* badEmail:' '--no-strict'
 
 ############################################################
 # 15. allow empty tag email
@@ -422,13 +427,21 @@ this line should not be here
 EOF
 
 check_verify_failure 'detect invalid header entry' \
-	'^error:.* extraHeaderEntry:'
+	'^error:.* extraHeaderEntry:' '--no-strict'
 
 test_expect_success 'invalid header entry config & fsck' '
 	test_must_fail git mktag <tag.sig &&
+	git mktag --no-strict <tag.sig &&
+
 	test_must_fail git -c fsck.extraHeaderEntry=error mktag <tag.sig &&
+	test_must_fail git -c fsck.extraHeaderEntry=error mktag --no-strict <tag.sig &&
+
 	test_must_fail git -c fsck.extraHeaderEntry=warn mktag <tag.sig &&
+	git -c fsck.extraHeaderEntry=warn mktag --no-strict <tag.sig &&
+
 	git -c fsck.extraHeaderEntry=ignore mktag <tag.sig &&
+	git -c fsck.extraHeaderEntry=ignore mktag --no-strict <tag.sig &&
+
 	git fsck &&
 	env GIT_TEST_GETTEXT_POISON=false \
 		git -c fsck.extraHeaderEntry=warn fsck 2>err &&