--- /dev/null
+# This work is licensed under the terms of the GNU LGPL, version 2 or later.
+# See the COPYING.LIB file in the top-level directory.
+
+# Diagnose member initialized twice in pattern + format.
+&args a
+@format ........ ........ a:16 &args
+insn 00000000 00000000 a:16 @format