Index: Objects/fileobject.c
===================================================================
--- Objects/fileobject.c	(revision 60072)
+++ Objects/fileobject.c	(working copy)
@@ -2244,7 +2244,10 @@
 			return -1;
 		}
 		Py_BEGIN_ALLOW_THREADS
-		fputs(s, fp);
+		if(fputs(s, fp) == EOF) {
+			err_closed();
+			return -1;
+		}
 		Py_END_ALLOW_THREADS
 		return 0;
 	}