Add a NEWS entry for r81758 and clarify a comment.
diff --git a/Misc/NEWS b/Misc/NEWS
index 1d5cc02..f22512b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,14 @@
 Core and Builtins
 -----------------
 
+- Issue #8271: during the decoding of an invalid UTF-8 byte sequence, only the
+  start byte and the continuation byte(s) are now considered invalid, instead
+  of the number of bytes specified by the start byte.
+  E.g.: '\xf1\x80AB'.decode('utf-8', 'replace') now returns u'\ufffdAB' and
+  replaces with U+FFFD only the start byte ('\xf1') and the continuation byte
+  ('\x80') even if '\xf1' is the start byte of a 4-bytes sequence.
+  Previous versions returned a single u'\ufffd'.
+
 - Issue #8627: Remove bogus "Overriding __cmp__ blocks inheritance of
   __hash__ in 3.x" warning.  Also fix "XXX undetected error" that
   arises from the "Overriding __eq__ blocks inheritance ..." warning