News about StopIteration as a "sink state".

diff --git a/Misc/NEWS b/Misc/NEWS
index 0a1ce88e11ba680e1f1550e7e10249291da0d8ab..f8f3b7f5d22269048484451dd56461609cd34146 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -6,6 +6,14 @@ Type/class unification and new-style classes
 
 Core and builtins
 
+- All standard iterators now ensure that, once StopIteration has been
+  raised, all future calls to next() on the same iterator will also
+  raise StopIteration.  There used to be various counterexamples to
+  this behavior, which could caused confusion or subtle program
+  breakage, without any benefits.  (Note that this is still an
+  iterator's responsibility; the iterator framework does not enforce
+  this.)
+
 - Ctrl+C handling on Windows has been made more consistent with
   other platforms.  KeyboardInterrupt can now reliably be caught,
   and Ctrl+C at an interative prompt no longer terminates the