See http://mail.gnome.org/archives/mc-devel/2006-October/msg00025.html

diff -Nru mc-4.6.1.orig/src/subshell.c mc-4.6.1/src/subshell.c
--- mc-4.6.1.orig/src/subshell.c	2006-11-21 08:13:35.498257460 +0100
+++ mc-4.6.1/src/subshell.c	2006-11-21 08:14:10.971977460 +0100
@@ -718,29 +718,13 @@
     memcpy (d, cmd_start, len);
     d += len;
 
-    /*
-     * Print every character in octal format with the leading backslash.
-     * tcsh and zsh may require 4-digit octals, bash < 2.05b doesn't like them.
-     */
-    if (subshell_type == BASH) {
 	for (; *s; s++) {
-	    /* Must quote numbers, so that they are not glued to octals */
 	    if (isalpha ((unsigned char) *s)) {
 		*d++ = (unsigned char) *s;
 	    } else {
-		sprintf (d, "\\%03o", (unsigned char) *s);
-		d += 4;
-	    }
-	}
-    } else {
-	for (; *s; s++) {
-	    if (isalnum ((unsigned char) *s)) {
-		*d++ = (unsigned char) *s;
-	    } else {
 		sprintf (d, "\\0%03o", (unsigned char) *s);
 		d += 5;
 	    }
-	}
     }
 
     memcpy (d, common_end, sizeof (common_end));