end of first pass on coverity reports. Daniel

* runtest.c schematron.c testAutomata.c tree.c valid.c xinclude.c
  xmlcatalog.c xmlreader.c xmlregexp.c xpath.c: end of first
  pass on coverity reports.
Daniel
diff --git a/valid.c b/valid.c
index 1bd0ef9..edf5426 100644
--- a/valid.c
+++ b/valid.c
@@ -4064,9 +4064,11 @@
 	     * element in the external subset.
 	     */
 	    nbId = 0;
-	    table = (xmlAttributeTablePtr) doc->intSubset->attributes;
-	    xmlHashScan3(table, NULL, NULL, attr->elem, (xmlHashScanner)
-		         xmlValidateAttributeIdCallback, &nbId);
+	    if (doc->intSubset != NULL) {
+		table = (xmlAttributeTablePtr) doc->intSubset->attributes;
+		xmlHashScan3(table, NULL, NULL, attr->elem, (xmlHashScanner)
+			     xmlValidateAttributeIdCallback, &nbId);
+	    }
 	}
 	if (nbId > 1) {