more coverage more fixes Daniel

* gentest.py testapi.c: more coverage
* debugXML.c parser.c xmlregexp.c xpath.c: more fixes
Daniel
diff --git a/xmlregexp.c b/xmlregexp.c
index b34cf9c..eb67fa4 100644
--- a/xmlregexp.c
+++ b/xmlregexp.c
@@ -4062,6 +4062,8 @@
 xmlRegexpPrint(FILE *output, xmlRegexpPtr regexp) {
     int i;
 
+    if (output == NULL)
+        return;
     fprintf(output, " regexp: ");
     if (regexp == NULL) {
 	fprintf(output, "NULL\n");