Add custom namespaces definitions

tests/test_util.py

@@ -7,10 +7,13 @@
 import logging.handlers
 import sys
 import unittest
+from lxml import etree
 from io import StringIO
 
+from wsgidav import xml_tools
 from wsgidav.util import (
     BASE_LOGGER_NAME,
+    add_property_response,
     check_tags,
     checked_etag,
     deep_update,
@@ -25,6 +28,7 @@
     pop_path,
     removeprefix,
     shift_path,
+    to_str,
     update_headers_in_place,
 )
 
@@ -180,6 +184,17 @@ def testBasics(self):
         assert get_dict_value(d, "c", as_dict=True) is False
         assert get_dict_value(d, "x", as_dict=True) == {}
         self.assertRaises(KeyError, get_dict_value, d, "x", as_dict=False)
+
+        multistatus_el = xml_tools.make_multistatus_el()
+        add_property_response(multistatus_el, "", [
+            ('{custom}name', etree.Element("{custom}name", nsmap={"C": "custom"}))
+        ])
+        assert to_str(xml_tools.xml_to_bytes(multistatus_el, pretty=False)) == (
+            '<?xml version=\'1.0\' encoding=\'UTF-8\'?>\n'
+            '<D:multistatus xmlns:D="DAV:"><D:response>'
+            '<D:href></D:href><D:propstat><D:prop><C:name xmlns:C="custom"/></D:prop><D:status>HTTP/1.1 200 OK</D:status></D:propstat>'
+            '</D:response></D:multistatus>'
+        )
 
 
 class LoggerTest(unittest.TestCase):

wsgidav/util.py

@@ -1306,7 +1306,7 @@ def add_property_response(multistatus_elem, href, prop_list):
     """
     # Split prop_list by status code and build a unique list of namespaces
     nsCount = 1
-    nsDict = {}
+    nsSet = set()
     nsMap = {}
     propDict = {}
 
@@ -1320,10 +1320,11 @@ def add_property_response(multistatus_elem, href, prop_list):
         # Collect namespaces, so we can declare them in the <response> for
         # compacter output
         ns, _ = split_namespace(name)
-        if ns != "DAV:" and ns not in nsDict and ns != "":
-            nsDict[ns] = True
-            nsMap[f"NS{nsCount}"] = ns
-            nsCount += 1
+        if ns != "DAV:" and ns not in nsSet and ns != "":
+            if not is_etree_element(value) or ns not in value.nsmap.values():
+                nsMap[f"NS{nsCount}"] = ns
+                nsCount += 1
+            nsSet.add(ns)
 
         propDict.setdefault(status, []).append((name, value))