diff -Naru "netcdf-c-4.7.3 copy/libdap4/ezxml.c" netcdf-c-4.7.3/libdap4/ezxml.c
--- "netcdf-c-4.7.3 copy/libdap4/ezxml.c"	2022-07-13 10:24:32.128424000 +0800
+++ netcdf-c-4.7.3/libdap4/ezxml.c	2022-07-13 10:24:57.220170000 +0800
@@ -574,7 +574,7 @@
             for (l = 0; *s && ((! l && *s != '>') || (l && (*s != ']' ||
                  *(s + strspn(s + 1, EZXML_WS) + 1) != '>')));
                  l = (*s == '[') ? 1 : l) s += strcspn(s + 1, "[]>") + 1;
-            if (! *s && e != '>')
+            if (! *s)
                 return ezxml_err(root, d, "unclosed <!DOCTYPE");
             d = (l) ? strchr(d, '[') + 1 : d;
             if (l && ! ezxml_internal_dtd(root, d, s++ - d)) return &root->xml;