add NEWS note
diff --git a/Misc/NEWS b/Misc/NEWS
index 76f2377..9c08b43 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -20,6 +20,9 @@
 Library
 -------
 
+- Issue #7348: StringIO.StringIO.readline(-1) now acts as if it got no argument
+  like other file objects.
+
 - Issue #7357: tarfile no longer suppresses fatal extraction errors by
   default.