small enhancement to prevent trying to print strings with null pointers

* testSAX.c: small enhancement to prevent trying to print
  strings with null pointers (caused "make tests" errors on
  HP-UX)
diff --git a/ChangeLog b/ChangeLog
index da93d29..466b026 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sat Feb 28 22:35:32 HKT 2004 William Brack <wbrack@mmm.com.hk>
+
+	* testSAX.c: small enhancement to prevent trying to print
+	  strings with null pointers (caused "make tests" errors on
+	  HP-UX)
+
 Thu Feb 26 20:19:40 MST 2004 John Fleck <jfleck@inkstain.net>
 
 	* doc/xmllint.xml
diff --git a/testSAX.c b/testSAX.c
index 538c8d7..accd2f3 100644
--- a/testSAX.c
+++ b/testSAX.c
@@ -437,6 +437,14 @@
 entityDeclDebug(void *ctx ATTRIBUTE_UNUSED, const xmlChar *name, int type,
           const xmlChar *publicId, const xmlChar *systemId, xmlChar *content)
 {
+const xmlChar *nullstr = BAD_CAST "(null)";
+    /* not all libraries handle printing null pointers nicely */
+    if (publicId == NULL)
+        publicId = nullstr;
+    if (systemId == NULL)
+        systemId = nullstr;
+    if (content == NULL)
+        content = (xmlChar *)nullstr;
     callbacks++;
     if (quiet)
 	return;
@@ -524,6 +532,14 @@
 		   const xmlChar *publicId, const xmlChar *systemId,
 		   const xmlChar *notationName)
 {
+const xmlChar *nullstr = BAD_CAST "(null)";
+
+    if (publicId == NULL)
+        publicId = nullstr;
+    if (systemId == NULL)
+        systemId = nullstr;
+    if (notationName == NULL)
+        notationName = nullstr;
     callbacks++;
     if (quiet)
 	return;