Fix ENCODE-TIME to correctly handle negative time zones.

This bug has been lying here for fifteen years.  Obviously we need
more MIT Scheme hackers in the western hemisphere...

All this time and date code desperately needs a lot of automatic
tests, too.

diff --git a/src/microcode/prosenv.c b/src/microcode/prosenv.c
index 72f9a1304fa7b0b5e2167fb5412a8ae894307a42..5de256ec889266e43248fb1ee6234860677ba482 100644 (file)
--- a/src/microcode/prosenv.c
+++ b/src/microcode/prosenv.c
@@ -116,8 +116,8 @@ DEFINE_PRIMITIVE ("ENCODE-TIME", Prim_encode_time, 1, 1,
   (ts . time_zone)
     = (((len > 9)
        && (INTEGER_P (VECTOR_REF (vec, 9)))
-       && (integer_to_ulong_p (VECTOR_REF (vec, 9))))
-       ? (integer_to_ulong (VECTOR_REF (vec, 9)))
+       && (integer_to_long_p (VECTOR_REF (vec, 9))))
+       ? (integer_to_long (VECTOR_REF (vec, 9)))
        : INT_MAX);
   PRIMITIVE_RETURN (intmax_to_integer (OS_encode_time (&ts)));
 }