HTTPRequest: close file uploads to prevent ResourceWarning

CHANGES.rst

@@ -10,6 +10,9 @@ https://github.com/zopefoundation/Zope/blob/4.x/CHANGES.rst
 5.11.2 (unreleased)
 -------------------
 
+- Fix a ``ResourceWarning`` emitted when uploading large files.
+  (`#1242 <https://github.com/zopefoundation/Zope/issues/1242>`_)
+
 - OFS/cachable: fix *Cache this object using* label in ZMI.
 
 - Include versions constraints for production and non-production dependencies

src/ZPublisher/HTTPRequest.py

@@ -192,6 +192,9 @@ def clear(self):
         self.stdin = None
         self._file = None
         self._fs = None
+        for f in self.form.values():
+            if isinstance(f, FileUpload):
+                f.close()
         self.form.clear()
         # we want to clear the lazy dict here because BaseRequests don't have
         # one.  Without this, there's the possibility of memory leaking

src/ZPublisher/tests/testHTTPRequest.py

@@ -903,7 +903,8 @@ def test_processInputs_w_large_input_gets_tempfile(self):
         self.assertTrue(f.name)
         self.assertEqual(40006, len(f.file.read()))
         self.assertTrue(f.file.fileno())
-        f.file.close()
+        req.clear()
+        self.assertTrue(f.file.closed)
 
     def test_processInputs_with_file_upload_gets_iterator(self):
         # checks fileupload object supports the iterator protocol