[libxml2] 567619 xmlValidateNotationUse missing param test

[Daniel Veillard <veillard src gnome org>]

commit eab3ac94c781e686c86c5a1502bf150f86750fd7
Author: Daniel Veillard <veillard redhat com>
Date:   Wed Aug 12 10:39:29 2009 +0200

    567619 xmlValidateNotationUse missing param test
    
    * valid.c: this was raised by a testapi crash on solaris

 valid.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/valid.c b/valid.c
index ea47142..289a96a 100644
--- a/valid.c
+++ b/valid.c
@@ -3399,7 +3399,8 @@ int
 xmlValidateNotationUse(xmlValidCtxtPtr ctxt, xmlDocPtr doc,
                        const xmlChar *notationName) {
     xmlNotationPtr notaDecl;
-    if ((doc == NULL) || (doc->intSubset == NULL)) return(-1);
+    if ((doc == NULL) || (doc->intSubset == NULL) ||
+        (notationName == NULL)) return(-1);
 
     notaDecl = xmlGetDtdNotationDesc(doc->intSubset, notationName);
     if ((notaDecl == NULL) && (doc->extSubset != NULL))