Issue #24580: Symbolic group references to open group in re patterns now are
explicitly forbidden as well as numeric group references.
diff --git a/Lib/sre_parse.py b/Lib/sre_parse.py
index c0f539d..67f84e9 100644
--- a/Lib/sre_parse.py
+++ b/Lib/sre_parse.py
@@ -675,6 +675,9 @@
if gid is None:
msg = "unknown group name %r" % name
raise source.error(msg, len(name) + 1)
+ if not state.checkgroup(gid):
+ raise source.error("cannot refer to an open group",
+ len(name) + 1)
state.checklookbehindgroup(gid, source)
subpatternappend((GROUPREF, gid))
continue