[AD] ex_utf8 fails

[Elias Pschernig <elias.pschernig@xxxxxxxxxx>]

Didn't investigate myself yet, but zap0 posted the below in #allegro.
All other tests work fine. He was on XP and compiled Allegro 4.9.19 with
MSVC9.

# t19

OK   al_ustr_insert_chr(us, 0, 'a') == 1
OK   al_ustr_insert_chr(us, 0, L'æ') == 2
FAIL al_ustr_insert_chr(us, 2, L'€') == 3
FAIL 0 == strcmp(al_cstr(us), "æ€a")
OK   al_ustr_insert_chr(us, 8, L'ö') == 2
FAIL 0 == memcmp(al_cstr(us), "æ€a\0\0ö", 9)
OK   al_ustr_insert_chr(us, 0, -1) == 0
OK   al_ustr_insert_chr(us, 0, 0x110000) == 0

# t20

OK   al_ustr_append_chr(us, 'a') == 1
OK   al_ustr_append_chr(us, L'æ') == 2
FAIL al_ustr_append_chr(us, L'€') == 3
FAIL 0 == strcmp(al_cstr(us), "aæ€")
OK   al_ustr_append_chr(us, -1) == 0
OK   al_ustr_append_chr(us, 0x110000) == 0

# t29

OK   al_ustr_get_next(us, &pos) == 'a'
FAIL al_ustr_get_next(us, &pos) == L'þ'
FAIL al_ustr_get_next(us, &pos) == L'€'
OK   al_ustr_get_next(us, &pos) == -1
OK   pos == (int) al_ustr_size(us)
OK   al_ustr_get_next(us, &pos) == -2
FAIL al_ustr_get_next(us, &pos) == L'€'

# t30

FAIL al_ustr_prev_get(us, &pos) == L'€'
FAIL al_ustr_prev_get(us, &pos) == L'þ'
OK   al_ustr_prev_get(us, &pos) == 'a'
OK   al_ustr_prev_get(us, &pos) == -1
FAIL al_ustr_prev_get(us, &pos) == L'þ'

# t31

OK   al_ustr_find_chr(us, 0, 'e') == 7
OK   al_ustr_find_chr(us, 7, 'e') == 7
OK   al_ustr_find_chr(us, 8, 'e') == 23
OK   al_ustr_find_chr(us, 0, '.') == -1
FAIL al_ustr_find_chr(us, 0, L'ð') == 5
FAIL al_ustr_find_chr(us, 5, L'ð') == 5
FAIL al_ustr_find_chr(us, 6, L'ð') == 21
OK   al_ustr_find_chr(us, 0, L'ƶ') == -1

# t32

OK   al_ustr_rfind_chr(us, end, 'e') == 23
OK   al_ustr_rfind_chr(us, 23, 'e') == 7
OK   al_ustr_rfind_chr(us, end, '.') == -1
FAIL al_ustr_rfind_chr(us, end, L'í') == 30
FAIL al_ustr_rfind_chr(us, end - 1, L'í') == 14
OK   al_ustr_rfind_chr(us, end, L'ƶ') == -1

# t42

OK   al_ustr_set_chr(us, 1, 'B') == 1
OK   0 == strcmp(al_cstr(us), "aBcdef")
OK   6 == al_ustr_size(us)
OK   al_ustr_set_chr(us, 1, L'β') == 2
FAIL 0 == strcmp(al_cstr(us), "aβcdef")
OK   7 == al_ustr_size(us)
FAIL al_ustr_set_chr(us, 5, L'á´ˆ') == 3
FAIL 0 == strcmp(al_cstr(us), "aβcdᴈf")
FAIL 9 == al_ustr_size(us)
OK   al_ustr_set_chr(us, 5, L'É™') == 2
FAIL 0 == strcmp(al_cstr(us), "aβcdəf")
OK   8 == al_ustr_size(us)
FAIL al_ustr_set_chr(us, al_ustr_size(us), L'á¿·') == 3
FAIL 0 == strcmp(al_cstr(us), "aβcdəfῷ")
FAIL 11 == al_ustr_size(us)
FAIL al_ustr_set_chr(us, al_ustr_size(us) + 2, L'⁑') == 3
FAIL 0 == memcmp(al_cstr(us), "aβcdəfῷ\0\0⁑", 16)
FAIL 16 == al_ustr_size(us)
OK   al_ustr_set_chr(us, -1, L'⁑') == 0
FAIL 16 == al_ustr_size(us)