Index: /trunk/psLib/test/dataManip/tst_psStats00.c
===================================================================
--- /trunk/psLib/test/dataManip/tst_psStats00.c	(revision 2722)
+++ /trunk/psLib/test/dataManip/tst_psStats00.c	(revision 2723)
@@ -172,7 +172,15 @@
                             "PS_STAT_SAMPLE_MEAN: NULL inputs");
 
-    myStats = psVectorStats(myStats, NULL, NULL, 0);
+    psLogMsg(__func__,PS_LOG_INFO,"Following should generate an error message.");
+    if( psVectorStats(myStats, NULL, NULL, 0) != myStats ) {
+        psError(PS_ERR_UNKNOWN,true,"psVectorStats did not return stats when input NULL");
+        return 10;
+    }
+    psLogMsg(__func__,PS_LOG_INFO,"Following should generate an error message.");
     psStats *myStats2 = psVectorStats(NULL, myVector, NULL, 0);
-
+    if ( myStats2 != NULL ) {
+        psError(PS_ERR_UNKNOWN,true,"psVectorStats did not return NULL");
+        return 20;
+    }
     printFooter(stdout,
                 "psVector functions",
Index: /trunk/psLib/test/dataManip/verified/tst_psStats00.stderr
===================================================================
--- /trunk/psLib/test/dataManip/verified/tst_psStats00.stderr	(revision 2723)
+++ /trunk/psLib/test/dataManip/verified/tst_psStats00.stderr	(revision 2723)
@@ -0,0 +1,8 @@
+<DATE><TIME>|<HOST>|I|main
+    Following should generate an error message.
+<DATE><TIME>|<HOST>|E|psVectorStats (psStats.c:<LINENO>)
+    Unallowable operation: psVector in or its data is NULL.
+<DATE><TIME>|<HOST>|I|main
+    Following should generate an error message.
+<DATE><TIME>|<HOST>|E|psVectorStats (psStats.c:<LINENO>)
+    Unallowable operation: stats is NULL.