wrc: Handle "no files == stdin".
diff --git a/tools/wrc/wrc.c b/tools/wrc/wrc.c
index 6a856eb..5879d92 100644
--- a/tools/wrc/wrc.c
+++ b/tools/wrc/wrc.c
@@ -514,6 +514,13 @@
             }
             if (load_file( input_name, output_name )) exit(1);
         }
+	/* stdin special case. NULL means "stdin" for wpp. */
+        if (nb_files == 0)
+        {
+            if(!output_name && !preprocess_only)
+		output_name = strdup("wrc.tab.res");
+            if (load_file( NULL, output_name )) exit(1);
+        }
 
 	if(debuglevel & DEBUGLEVEL_DUMP)
 		dump_resources(resource_top);