SAFE_ALLOCA_LISP (args, args_alloc);
ptrdiff_t nmapped = mapcar1 (leni, args, function, sequence);
ptrdiff_t nargs = 2 * nmapped - 1;
+ eassert (nmapped == leni);
- for (ptrdiff_t i = nmapped - 1; i > 0; i--)
- args[i + i] = args[i];
+ if (!NILP (Fequal (separator, empty_multibyte_string)))
+ nargs = nmapped;
+ else
+ {
+ for (ptrdiff_t i = nmapped - 1; i > 0; i--)
+ args[i + i] = args[i];
- for (ptrdiff_t i = 1; i < nargs; i += 2)
- args[i] = separator;
+ for (ptrdiff_t i = 1; i < nargs; i += 2)
+ args[i] = separator;
+ }
Lisp_Object ret = Fconcat (nargs, args);
SAFE_FREE ();