a lot of fixing of batch mode

Author: jcupitt

TODO

@@ -1,5 +1,17 @@
+- expect:
+
+        $ nip2 --test test_snip.def
+        $ echo $?
+        0
+        $ nip2 --test test_snip.def --print-main
+        all tests pass
+
 - open test.ws, edit defs, "main = 12;", process, ws is not marked as modified
 
+- need to find and print "main" after all files have been loaded
+
+- use main_log_add() consistently, print on exit
+
 - check all batch mode flags
 
 - try to save and restore image view scale and position

src/heap.c

@@ -2648,11 +2648,8 @@ graph_value(PElement *root)
 {
 	Reduce *rc = reduce_context;
 
-	if (!reduce_pelement(rc, reduce_spine_strict, root)) {
-		printf("graph_value: iwindow_alert FIXME\n");
-		// iwindow_alert(NULL, GTK_MESSAGE_ERROR);
-		return;
-	}
+	if (!reduce_pelement(rc, reduce_spine_strict, root))
+		error_alert(NULL);
 
 	heap_clear(reduce_context->heap, FLAG_PRINT);
 	shell_pelement(root);