Index: ext/xsl/php_xsl.c
===================================================================
RCS file: /repository/php-src/ext/xsl/php_xsl.c,v
retrieving revision 1.15
diff -u -r1.15 php_xsl.c
--- ext/xsl/php_xsl.c	9 Dec 2003 20:12:39 -0000	1.15
+++ ext/xsl/php_xsl.c	10 Dec 2003 21:00:22 -0000
@@ -247,6 +247,16 @@
 	fci.function_table = EG(function_table);
 	
 	obj = valuePop(ctxt);
+	if (obj->stringval == NULL) {
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "Handler name must be a string");
+		xmlXPathFreeObject(obj);
+		for (i = 0; i < nargs - 1; i++) {
+			zval_ptr_dtor(&args[i]);
+		}
+		efree(args);
+		efree(fci.params);
+		return; 
+	}
 	INIT_PZVAL(&handler);
 	ZVAL_STRING(&handler, obj->stringval, 1);
 	xmlXPathFreeObject(obj);