Reduce side effects for rl_basic_word_break_characters

Modules/readline.c

@@ -576,7 +576,13 @@ readline_set_completer_delims(PyObject *module, PyObject *string)
     if (break_chars) {
         free(completer_word_break_characters);
         completer_word_break_characters = break_chars;
+#ifdef WITH_EDITLINE
         rl_basic_word_break_characters = break_chars;
+#else
+        if (using_libedit_emulation) {
+            rl_basic_word_break_characters = break_chars;
+        }
+#endif
         rl_completer_word_break_characters = break_chars;
         Py_RETURN_NONE;
     }
@@ -1268,7 +1274,15 @@ setup_readline(readlinestate *mod_state)
     completer_word_break_characters =
         strdup(" \t\n`~!@#$%^&*()-=+[{]}\\|;:'\",<>/?");
         /* All nonalphanums except '.' */
+#ifdef WITH_EDITLINE
+    // libedit uses rl_basic_word_break_characters instead of
+    // rl_completer_word_break_characters as complete delimiter
     rl_basic_word_break_characters = completer_word_break_characters;
+#else
+    if (using_libedit_emulation) {
+        rl_basic_word_break_characters = completer_word_break_characters;
+    }
+#endif
     rl_completer_word_break_characters = completer_word_break_characters;
 
     mod_state->begidx = PyLong_FromLong(0L);