Fix swagger UI for split specs

connexion/middleware/swagger_ui.py

@@ -63,14 +63,14 @@ def _base_path_for_prefix(self, request: StarletteRequest) -> str:
             "route_root_path", request.scope.get("root_path", "")
         ).rstrip("/")
 
-    def _spec_for_prefix(self, request):
+    def _spec_for_prefix(self, request) -> dict:
         """
         returns a spec with a modified basePath / servers block
         which corresponds to the incoming request path.
         This is needed when behind a path-altering reverse proxy.
         """
         base_path = self._base_path_for_prefix(request)
-        return self.specification.with_base_path(base_path).raw
+        return self.specification.with_base_path(base_path)
 
     def add_openapi_json(self):
         """

connexion/spec.py

@@ -203,9 +203,6 @@ def enforce_string_keys(obj):
             return Swagger2Specification(spec, base_uri=base_uri)
         return OpenAPISpecification(spec, base_uri=base_uri)
 
-    def clone(self):
-        return type(self)(copy.deepcopy(self._raw_spec))
-
     @classmethod
     def load(cls, spec, *, arguments=None):
         if isinstance(spec, str) and (
@@ -217,9 +214,9 @@ def load(cls, spec, *, arguments=None):
             return cls.from_file(spec, arguments=arguments, base_uri=base_uri)
         return cls.from_dict(spec)
 
-    def with_base_path(self, base_path):
-        new_spec = self.clone()
-        new_spec.base_path = base_path
+    def with_base_path(self, base_path) -> dict:
+        new_spec = copy.deepcopy(self._spec)
+        new_spec["base_path"] = base_path
         return new_spec
 
     @property