updated for version 7.3.859
Problem:    'ambiwidth' must be set by the user.
Solution:   Detects East Asian ambiguous width (UAX #11) state of the terminal
            at the start-up time and 'ambiwidth' accordingly.  (Hayaki Saito)
diff --git a/src/option.c b/src/option.c
index adb501b..f9d9fd5 100644
--- a/src/option.c
+++ b/src/option.c
@@ -2900,6 +2900,7 @@
     p_term("t_op", T_OP)
     p_term("t_RI", T_CRI)
     p_term("t_RV", T_CRV)
+    p_term("t_u7", T_U7)
     p_term("t_Sb", T_CSB)
     p_term("t_Sf", T_CSF)
     p_term("t_se", T_SE)