logxor: fix seriously broken function.

Reported by Guillaume le Vaillant.

* arith.c (logxor): Fix broken behavior when the arguments are
the same nonzero fixnum, or the same bignum object.
(logxor_old): New function: verbatim copy of previous logxor.

* eval.c (eval_init): Register logxor intrinsic to the broken
function if compatibility is 202 or less.

* txr.1: Compat note added.

1 files changed, 2 insertions, 1 deletions

diff --git a/eval.c b/eval.c
index 637ed8a6..0dc68559 100644
--- a/eval.c
+++ b/eval.c
@@ -6476,7 +6476,8 @@ void eval_init(void)
   reg_fun(intern(lit("in"), user_package), func_n4o(in, 2));
   reg_fun(intern(lit("logand"), user_package), func_n0v(logandv));
   reg_fun(intern(lit("logior"), user_package), func_n0v(logiorv));
-  reg_fun(intern(lit("logxor"), user_package), func_n2(logxor));
+  reg_fun(intern(lit("logxor"), user_package),
+          func_n2(if3(opt_compat && opt_compat <= 202, logxor_old, logxor)));
   reg_fun(intern(lit("logtest"), user_package), func_n2(logtest));
   reg_fun(intern(lit("lognot"), user_package), func_n2o(lognot, 1));
   reg_fun(intern(lit("logtrunc"), user_package), func_n2(logtrunc));