suppress shell expansion inside quoted strings

grub-core/script/execute.c

@@ -374,7 +374,7 @@ grub_script_arglist_to_argv (struct grub_script_arglist *arglist,
 
 	    case GRUB_SCRIPT_ARG_TYPE_DQSTR:
 	    case GRUB_SCRIPT_ARG_TYPE_SQSTR:
-	      if (grub_script_argv_append (&result, arg->str))
+	      if (append (arg->str, 1))
 		goto fail;
 	      break;
 	    }

tests/grub_cmd_echo.in

@@ -31,3 +31,11 @@ echo foo -n
 echo foo -n -e
 
 echo -------
+
+if test -n "$grubshell"; then insmod regexp; fi
+
+echo '*'
+echo "*"
+
+foo="*"
+echo "$foo"