Infinite loop in __argp_get_display_len

[Mike Gilbert]

Running grub-mkimage --help triggers an infinite loop in
__argp_get_display_len. Backtrace attached.

The following change seems to resolve it; I wonder if it should be
applied to the other functions in argp-fmtstream.c?

=== modified file 'grub-core/gnulib/argp-fmtstream.c'
--- grub-core/gnulib/argp-fmtstream.c   2012-02-26 18:07:59 +0000
+++ grub-core/gnulib/argp-fmtstream.c   2012-02-26 19:04:10 +0000
@@ -133,7 +133,7 @@
       size_t s;

       s = mbrtowc (&wc, ptr, end - ptr, &ps);
-      if (s == (size_t) -1)
+      if (s == 0 || s == (size_t) -1 || s == (size_t) -2)
        break;
       r += wcwidth (wc);
       ptr += s;

gdb.txt
Description: Text document