MIRAX read_slide_position_file

[Marco Feuerstein]

Hi Adam,

I'm a colleague of Hauke also starting to work with/on openslide.
With some of our MIRAX files here I ran into a problem when using
"read_slide_position_file" in "openslide-vendor-mirax.c".
In line 570 when reading zz, it gives me 255 and not 0 as expected (where x
is 1 and y is -256). Do you know what's going wrong/different here? What
exactly do those numbers (x, y, zz) stand for?
If I change

-    if ((x == -1) || (y == -1) || (zz != 0) || (fread_result != 1)) {
+    if ((x == -1) || (y == -1) || (zz != 0 && zz != 255) || (fread_result
!= 1)) {

it works, but I'm not sure whether this is the correct fix.
Thanks a lot for your help!

Regards,
Marco