Closes #12579. Positional fields with str.format_map() now raise a ValueError instead of SystemError.

1 files changed, 4 insertions, 0 deletions

diff --git a/Misc/NEWS b/Misc/NEWS
index bf33745..f444709 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@ What's New in Python 3.2.2?
 Core and Builtins
 -----------------
 
+- Issue #12579: str.format_map() now raises a ValueError if used on a
+  format string that contains positional fields. Initial patch by
+  Julian Berman.
+
 - Issue #11627: Fix segfault when __new__ on a exception returns a non-exception
   class.