--- xml/apr_xml.c	(revision 509385)
+++ xml/apr_xml.c	(working copy)
@@ -666,7 +666,8 @@
 	    }
 	    else {
 		/* compute size of: ' ns%d:%s="%s"' */
-		size += 3 + APR_XML_NS_LEN(attr->ns) + 1 + strlen(attr->name) + 2 + strlen(attr->value) + 1;
+                int ns = ns_map ? ns_map[attr->ns] : attr->ns;
+		size += 3 + APR_XML_NS_LEN(ns) + 1 + strlen(attr->name) + 2 + strlen(attr->value) + 1;
 	    }
 	}
 
@@ -736,8 +737,11 @@
 	for (attr = elem->attr; attr; attr = attr->next) {
 	    if (attr->ns == APR_XML_NS_NONE)
 		len = sprintf(s, " %s=\"%s\"", attr->name, attr->value);
-	    else
-		len = sprintf(s, " ns%d:%s=\"%s\"", attr->ns, attr->name, attr->value);
+	    else 
+            {
+                ns = ns_map ? ns_map[attr->ns] : attr->ns;
+		len = sprintf(s, " ns%d:%s=\"%s\"", ns, attr->name, attr->value);
+            }
 	    s += len;
 	}