Back out fix for issue #13886; it introduced a new bug in interactive readline use.
diff --git a/Misc/NEWS b/Misc/NEWS
index 624c5a9..b11f6a2 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -11,9 +11,6 @@
 
 - Issue #16979: Fix error handling bugs in the unicode-escape-decode decoder.
 
-- Issue #13886: Fix input() to not strip out input bytes that cannot be decoded
-  using the locale encoding.
-
 - Issue #10156: In the interpreter's initialization phase, unicode globals
   are now initialized dynamically as needed.
 
diff --git a/Modules/readline.c b/Modules/readline.c
index 3cb6236..b5e258d 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -1041,7 +1041,7 @@
     char *saved_locale = strdup(setlocale(LC_CTYPE, NULL));
     if (!saved_locale)
         Py_FatalError("not enough memory to save locale");
-    setlocale(LC_CTYPE, "C");
+    setlocale(LC_CTYPE, "");
 #endif
 
     if (sys_stdin != rl_instream || sys_stdout != rl_outstream) {