Bug#806487: syslinux: FTBFS: ldlinux.raw: write error

[Alex Andreotti <alex.andreotti@gmail.com>]

I've the same error with buildroot's syslinux, the problem is in
the file prepcore.c, in particular:

    if (fwrite(infile + start, 1, offset - start, f) != offset - start ||
    fwrite(out, 1, outfile_len, f) != outfile_len || fclose(f))
    error("write error");

given the code seems obvious an offset > start is expected, but a
printf show otherwise:

    infile=0x1cf0240 start=31744 out=0x7f3db1d6e010 offset=0
	    outfile_len=57639

offset is initialized with pfx_compressed:

    offset = get_32(&prefix->pfx_compressed);

something changed in some file format or some header?
or something about the arch being 64bit?
(objcopy doesn't fail)

    -rw-r--r-- 1 alex alex 250589 Dec 15 13:05 ldlinux.lsr
    -rw-r--r-- 1 alex alex 250589 Dec 15 13:05 ldlinux.lst
    -rw-r--r-- 1 alex alex   4136 Dec 15 13:05 ldlinux.sec
    -rwxr-xr-x 1 alex alex 687828 Dec 15 13:05 ldlinux.elf
    -rw-r--r-- 1 alex alex 127464 Dec 15 13:05 ldlinux.raw
    -rw-r--r-- 1 alex alex      0 Dec 15 13:05 ldlinux.bin