diff -r 07b815faa6ac -r f00d03835dd9 src/server/webdav/multistatus.c
--- a/src/server/webdav/multistatus.c	Tue Dec 30 21:44:49 2025 +0100
+++ b/src/server/webdav/multistatus.c	Tue Jan 13 18:09:20 2026 +0100
@@ -522,7 +522,7 @@
         const xmlChar *href,
         const char *property_name)
 {
-    cxmutstr key_data = cx_strcat_a(a, 3, cx_str((const char*)href), (cxstring){ "\0", 1 }, cx_str(property_name));
+    cxmutstr key_data = cx_strcat_a(a, CX_NULLSTR, 3, cx_str((const char*)href), (cxstring){ "\0", 1 }, cx_str(property_name));
     return cx_hash_key_bytes((unsigned char*)key_data.ptr, key_data.length);
 }