lib: new ldiff function.

* eval.c (eval_init): Use the old ldiff function under
compatibility with 190 or lower.

* lib.c (ldiff): Rewritten.
(ldiff_old): New function, copy of previous version of ldiff.

* lib.h (ldiff_old): Declared.

1 files changed, 2 insertions, 1 deletions

diff --git a/eval.c b/eval.c
index b04b15a2..b4233e42 100644
--- a/eval.c
+++ b/eval.c
@@ -6073,7 +6073,8 @@ void eval_init(void)
   reg_fun(intern(lit("copy-list"), user_package), func_n1(copy_list));
   reg_fun(intern(lit("nreverse"), user_package), func_n1(nreverse));
   reg_fun(intern(lit("reverse"), user_package), func_n1(reverse));
-  reg_fun(intern(lit("ldiff"), user_package), func_n2(ldiff));
+  reg_fun(intern(lit("ldiff"), user_package),
+          func_n2(if3(opt_compat && opt_compat <= 190, ldiff_old, ldiff)));
   reg_fun(intern(lit("last"), user_package), func_n2o(last, 1));
   reg_fun(intern(lit("butlast"), user_package), func_n2o(butlast, 1));
   reg_fun(intern(lit("nthlast"), user_package), func_n2(nthlast));