Issue #13886: Fix input() to not strip out supposedly-invalid input bytes.
Also fix sporadic failures in test_builtin due to dependence on whether the
readline module has previously been imported.
diff --git a/Modules/readline.c b/Modules/readline.c
index 4d54dad..fd60377 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -1068,7 +1068,7 @@
char *saved_locale = strdup(setlocale(LC_CTYPE, NULL));
if (!saved_locale)
Py_FatalError("not enough memory to save locale");
- setlocale(LC_CTYPE, "");
+ setlocale(LC_CTYPE, "C");
#endif
if (sys_stdin != rl_instream || sys_stdout != rl_outstream) {