Issue #5859: Remove use of fixed-length buffers for float formatting
in unicodeobject.c and the fallback version of PyOS_double_to_string.
As a result, operations like '%.120e' % 12.34 no longer raise an
exception.
diff --git a/Misc/NEWS b/Misc/NEWS
index 257762b..3e8f5e6 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and Builtins
 -----------------
 
+- Issue #5859: Remove length restrictions for float formatting:
+  '%.67f' % 12.34 and '%.120e' % 12.34 no longer raise an exception.
+
 - Issue #1588: Add complex.__format__. For example, 
   format(complex(1, 2./3), '.5') now produces a sensible result.