[PATCH] _rl_untranslate_macro_value with meta control chars

[Grisha Levit]

When printing a macro, any character with the 8th bit set will be printed
as `\M-' followed by the literal "unmetafied" character, even if the latter
is a control character:

$ bind '"_": "\201"'; bind -s | cat -v
"_": "\M-^A"

Or is a null byte:

$ bind '"1PI": "π"'; bind -s
"1PI": "\M-O\M-"

$ bind '"2PI": "ππ"'; bind -s
"2PI": "\M-O\M-"

---
diff --git a/lib/readline/bind.c b/lib/readline/bind.c
index a8b139f0..4811370b 100644
--- a/lib/readline/bind.c
+++ b/lib/readline/bind.c
@@ -732,7 +732,7 @@ _rl_untranslate_macro_value (char *seq, int use_escapes)
   char *ret, *r, *s;
   int c;

-  r = ret = (char *)xmalloc (7 * strlen (seq) + 1);
+  r = ret = (char *)xmalloc (10 * strlen (seq) + 1);
   for (s = seq; *s; s++)
     {
       c = *s;
@@ -743,7 +743,8 @@ _rl_untranslate_macro_value (char *seq, int use_escapes)
          *r++ = '-';
          c = UNMETA (c);
        }
-      else if (c == ESC)
+
+      if (c == ESC)
        {
          *r++ = '\\';
          c = 'e';
@@ -768,12 +769,7 @@ _rl_untranslate_macro_value (char *seq, int use_escapes)
          c = '?';
        }

-      if (c == ESC)
-       {
-         *r++ = '\\';
-         c = 'e';
-       }
-      else if (c == '\\' || c == '"')
+      if (c == '\\' || c == '"')
        *r++ = '\\';

       *r++ = (unsigned char)c;