[PATCH] msvcrt/tests: Add tests for mbstowcs and wcstombs with a negative count.

[Alex Henrie]

2016-06-13 4:21 GMT-06:00 Piotr Caban <piotr.caban at gmail.com>:
> On 06/12/16 22:07, Alex Henrie wrote:
>>
>> +    ret = mbstowcs(wOut, mSimple, -1);
>> +todo_wine
>> +    ok(ret == -1 || broken(ret == 4) /* xp */, "mbstowcs returned %i
>> instead of -1\n", ret);
>
> This will cause compilation warning:
> ../../../../wine_src/dlls/msvcrt/tests/string.c:1863:5: warning: format '%i'
> expects argument of type 'int', but argument 3 has type 'size_t' [-Wformat=]
>      ok(ret == -1 || broken(ret == 4) /* xp */, "mbstowcs returned %i
> instead of -1\n", ret);

Good point. I will rewrite this to just say "mbstowcs did not return
-1\n", similar to the surrounding tests.

> I'm also not sure if Windows XP behavior should be marked as broken. For me
> newer systems behavior is broken (doesn't handle strings longer then
> INT_MAX). Do you have an application that depends on it?

I discovered this while trying to figure out what's wrong with the
Emergency 3 Demo: https://bugs.winehq.org/show_bug.cgi?id=40775

The bug would be "fixed" if we adopted the Windows XP behavior for
mbstowcs. However, this application works fine on both Windows XP and
Windows 7, so I think that there is actually something else going on
here.

I really don't know which behavior should be considered "correct".
Windows XP's behavior matches the C specification, but Vista and later
all consistently do something else. Maybe we should make Wine behave
differently too depending on which version of Windows is selected in
winecfg, and put "ret == 4 || ret == -1" in the tests, omitting the
broken() macro. What do you think?

-Alex