Fixes hanging on no content

fastwsgi/request.c

@@ -163,6 +163,8 @@ int on_message_complete(llhttp_t* parser) {
 };
 
 void build_response(PyObject* wsgi_response, StartResponse* response, llhttp_t* parser) {
+    // This function needs a clean up
+
     logger("building response");
     Request* request = (Request*)parser->data;
 
@@ -176,10 +178,16 @@ void build_response(PyObject* wsgi_response, StartResponse* response, llhttp_t*
     else
         iter = PyObject_GetIter(wsgi_response);
 
-    if (result == NULL)
-        result = PyIter_Next(iter);
-
     int response_has_no_content = 0;
+
+    if (result == NULL) {
+        PyObject* next = PyIter_Next(iter);
+        if (next == NULL)
+            response_has_no_content = 1;
+        else
+            result = next;
+    }
+
     PyObject* status = PyUnicode_AsUTF8String(response->status);
     char* status_code = PyBytes_AS_STRING(status);
     if (strncmp(status_code, "204", 3) == 0 || strncmp(status_code, "304", 3) == 0) {
@@ -227,8 +235,8 @@ void build_response(PyObject* wsgi_response, StartResponse* response, llhttp_t*
 
     if (response_has_no_content) {
         char* old_buf = buf;
-        buf = malloc(strlen(old_buf) + 5);
-        sprintf(buf, "%s\r\n\r\n", old_buf);
+        buf = malloc(strlen(old_buf) + 26);
+        sprintf(buf, "%s\r\nContent-Length: 0\r\n\r\n", old_buf);
         free(old_buf);
     }
     else {

tests/apps_under_test/__init__.py

@@ -3,3 +3,4 @@ from .wsgi_app import wsgi_app
 from .flask_app import app as flask_app
 from .wsgi_validator_app import validator_app
 from .start_response_test_app import start_response_app
+from .general_test_app import general_test_app

tests/apps_under_test/general_test_app.py

@@ -0,0 +1,13 @@
+def _no_response(environ, start_response):
+    start_response("200 OK", [])
+    return []
+
+
+routes = {
+    "/no_response": _no_response,
+}
+
+
+def general_test_app(environ, start_response):
+    app = routes.get(environ["PATH_INFO"])
+    return app(environ, start_response)

tests/conftest.py

@@ -13,7 +13,8 @@ from tests.apps_under_test import (
     wsgi_app,
     flask_app,
     validator_app,
-    start_response_app
+    start_response_app,
+    general_test_app
 )
 
 HOST = "127.0.0.1"
@@ -40,6 +41,7 @@ class Servers(Enum):
     FLASK_TEST_SERVER = 3
     VALIDATOR_TEST_SERVER = 4
     START_RESPONSE_SERVER = 5
+    GENERAL_TEST_APP = 6
 
 
 servers = {
@@ -48,6 +50,7 @@ servers = {
     Servers.FLASK_TEST_SERVER: flask_app,
     Servers.VALIDATOR_TEST_SERVER: validator_app,
     Servers.START_RESPONSE_SERVER: start_response_app,
+    Servers.GENERAL_TEST_APP: general_test_app,
 }
 
 
@@ -107,3 +110,8 @@ def validator_test_server():
 @pytest.fixture
 def start_response_server():
     return servers.get(Servers.START_RESPONSE_SERVER)
+
+
+@pytest.fixture
+def general_test_server():
+    return servers.get(Servers.GENERAL_TEST_APP)

tests/test_general_app.py

@@ -0,0 +1,8 @@
+import requests
+
+
+def test_no_response(general_test_server):
+    url = f"{general_test_server.endpoint}/no_response"
+    result = requests.get(url)
+    assert result.status_code == 200
+    assert result.text is ''