commit 3f06523c090bbbb5d7651f30f3c2c498ae55d9ce
from: Martijn van Duren <martijn@openbsd.org>
date: Tue Nov  3 14:53:14 2026 UTC

Do a duplicate check for extends

commit - 9cbe8e42c45faa5c3bb540ba04e8aa30b4844671
commit + 3f06523c090bbbb5d7651f30f3c2c498ae55d9ce
blob - 96535458ce8b20f92c14a6641be71e94f5c67764
blob + 4de49cb60c90618aff96a3404061a317553527cc
--- parse.y
+++ parse.y
@@ -337,7 +337,11 @@ command		: STRING '{' optnl {
 				}
 			}
 
-			RB_INSERT(commands, &conf->commands, command);
+			command = RB_INSERT(commands, &conf->commands, command);
+			if (command != NULL) {
+				yyerror("Duplicate extend: %s", extend->token);
+				YYERROR;
+			}
 			command = NULL;
 		}
 		;