fix crash with null arithmetic for expression; fix size_t issue with history search string allocation

lib/readline/display.c

@@ -1093,6 +1093,8 @@ rl_redisplay (void)
 	      wc_width = (temp >= 0) ? temp : 1;
 	    }
 	}
+      else
+	wc_width = 1;		/* make sure it's set for the META_CHAR check */
 #endif
 
       if (in == rl_point)
@@ -1102,12 +1104,22 @@ rl_redisplay (void)
 	}
 
 #if defined (HANDLE_MULTIBYTE)
-      if (META_CHAR (c) && _rl_output_meta_chars == 0)	/* XXX - clean up */
+      if (META_CHAR (c) && wc_bytes == 1 && wc_width == 1)
 #else
       if (META_CHAR (c))
 #endif
 	{
+#if 0
+	  /* TAG: readline-8.3 20230227 */
+	  /* https://savannah.gnu.org/support/index.php?110830
+	     asking for non-printing meta characters to be printed using an
+	     escape sequence. */
+
+	  /* isprint(c) handles bytes up to UCHAR_MAX */
+	  if (_rl_output_meta_chars == 0 || isprint (c) == 0)
+#else
 	  if (_rl_output_meta_chars == 0)
+#endif
 	    {
 	      char obuf[5];
 	      int olen;

lib/readline/search.c

@@ -621,7 +621,7 @@ rl_history_search_reinit (int flags)
   if (rl_point)
     {
       /* Allocate enough space for anchored and non-anchored searches */
-      if (_rl_history_search_len >= history_string_size - 2)
+      if (_rl_history_search_len + 2 >= history_string_size)
 	{
 	  history_string_size = _rl_history_search_len + 2;
 	  history_search_string = (char *)xrealloc (history_search_string, history_string_size);