Since we no longer set the APP_NUM attribute in the case of a singleton, protect the code so we don't crash in that case.

This commit was SVN r16461.

orte/test/mpi/hello_nodename.c

@@ -14,17 +14,28 @@ int main(int argc, char* argv[])
     char hostname[512];
     void *appnum;
     void *univ_size;
+    char *appstr, *unistr;
     int flag;
 
     MPI_Init(&argc, &argv);
     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
     MPI_Comm_size(MPI_COMM_WORLD, &size);
     MPI_Comm_get_attr(MPI_COMM_WORLD, MPI_APPNUM, &appnum, &flag);
+    if (NULL == appnum) {
+        asprintf(&appstr, "UNDEFINED");
+    } else {
+        asprintf(&appstr, "%d", *(int*)appnum);
+    }
     MPI_Comm_get_attr(MPI_COMM_WORLD, MPI_UNIVERSE_SIZE, &univ_size, &flag);
-
+    if (NULL == univ_size) {
+        asprintf(&unistr, "UNDEFINED");
+    } else {
+        asprintf(&unistr, "%d", *(int*)univ_size);
+    }
+    
     gethostname(hostname, 512);
-    printf("Hello, World, I am %d of %d on host %s from app number %d universe size %d\n",
+    printf("Hello, World, I am %d of %d on host %s from app number %s universe size %s\n",
-                            rank, size, hostname, *(int*)appnum, *(int*)univ_size);
+                            rank, size, hostname, appstr, unistr);
 
     MPI_Finalize();
     return 0;