diff --git a/t/t0300-credentials.sh b/t/t0300-credentials.sh
index 82eaaea..4593a0c 100755
--- a/t/t0300-credentials.sh
+++ b/t/t0300-credentials.sh
@@ -240,6 +240,57 @@
 	EOF
 '
 
+test_expect_success 'match multiple configured helpers' '
+	test_config credential.helper "verbatim \"\" \"\"" &&
+	test_config credential.https://example.com.helper "$HELPER" &&
+	check fill <<-\EOF
+	protocol=https
+	host=example.com
+	path=repo.git
+	--
+	protocol=https
+	host=example.com
+	username=foo
+	password=bar
+	--
+	verbatim: get
+	verbatim: protocol=https
+	verbatim: host=example.com
+	EOF
+'
+
+test_expect_success 'match multiple configured helpers with URLs' '
+	test_config credential.https://example.com/repo.git.helper "verbatim \"\" \"\"" &&
+	test_config credential.https://example.com.helper "$HELPER" &&
+	check fill <<-\EOF
+	protocol=https
+	host=example.com
+	path=repo.git
+	--
+	protocol=https
+	host=example.com
+	username=foo
+	password=bar
+	--
+	verbatim: get
+	verbatim: protocol=https
+	verbatim: host=example.com
+	EOF
+'
+
+test_expect_success 'match percent-encoded values' '
+	test_config credential.https://example.com/%2566.git.helper "$HELPER" &&
+	check fill <<-\EOF
+	url=https://example.com/%2566.git
+	--
+	protocol=https
+	host=example.com
+	username=foo
+	password=bar
+	--
+	EOF
+'
+
 test_expect_success 'pull username from config' '
 	test_config credential.https://example.com.username foo &&
 	check fill <<-\EOF
@@ -255,6 +306,63 @@
 	EOF
 '
 
+test_expect_success 'honors username from URL over helper (URL)' '
+	test_config credential.https://example.com.username bob &&
+	test_config credential.https://example.com.helper "verbatim \"\" bar" &&
+	check fill <<-\EOF
+	url=https://alice@example.com
+	--
+	protocol=https
+	host=example.com
+	username=alice
+	password=bar
+	--
+	verbatim: get
+	verbatim: protocol=https
+	verbatim: host=example.com
+	verbatim: username=alice
+	EOF
+'
+
+test_expect_success 'honors username from URL over helper (components)' '
+	test_config credential.https://example.com.username bob &&
+	test_config credential.https://example.com.helper "verbatim \"\" bar" &&
+	check fill <<-\EOF
+	protocol=https
+	host=example.com
+	username=alice
+	--
+	protocol=https
+	host=example.com
+	username=alice
+	password=bar
+	--
+	verbatim: get
+	verbatim: protocol=https
+	verbatim: host=example.com
+	verbatim: username=alice
+	EOF
+'
+
+test_expect_failure 'last matching username wins' '
+	test_config credential.https://example.com/path.git.username bob &&
+	test_config credential.https://example.com.username alice &&
+	test_config credential.https://example.com.helper "verbatim \"\" bar" &&
+	check fill <<-\EOF
+	url=https://example.com/path.git
+	--
+	protocol=https
+	host=example.com
+	username=alice
+	password=bar
+	--
+	verbatim: get
+	verbatim: protocol=https
+	verbatim: host=example.com
+	verbatim: username=alice
+	EOF
+'
+
 test_expect_success 'http paths can be part of context' '
 	check fill "verbatim foo bar" <<-\EOF &&
 	protocol=https