fix unstrip_protocol when no default port set

dvc_ssh/__init__.py

@@ -41,9 +41,14 @@ def _strip_protocol(cls, path: str) -> str:
 
     def unstrip_protocol(self, path: str) -> str:
         host = self.fs_args["host"]
-        port = self.fs_args["port"]
+        port = self.fs_args.get("port")
         path = path.lstrip("/")
-        return f"ssh://{host}:{port}/{path}"
+
+        url = f"ssh://{host}"
+        if port:
+            url += f":{port}"
+        url += f"/{path}"
+        return url
 
     def _prepare_credentials(self, **config):
         from .client import InteractiveSSHClient

dvc_ssh/tests/test_fs.py

@@ -103,3 +103,17 @@ def test_ssh_keyfile(config, expected_keyfile):
 def test_ssh_gss_auth(config, expected_gss_auth):
     fs = SSHFileSystem(**config)
     assert fs.fs_args["gss_auth"] == expected_gss_auth
+
+
+@pytest.mark.parametrize(
+    "config,path,expected_path",
+    [
+        ({"host": "example.com"}, "path", "ssh://example.com/path"),
+        ({"host": "example.com"}, "/path", "ssh://example.com/path"),
+        ({"host": "example.com", "port": 1234}, "path", "ssh://example.com:1234/path"),
+        ({"host": "example.com", "port": 1234}, "/path", "ssh://example.com:1234/path"),
+    ],
+)
+def test_unstrip_protocol(mocker, config, path, expected_path):
+    fs = SSHFileSystem(**config, fs=mocker.MagicMock())
+    assert fs.unstrip_protocol(path) == expected_path