[PATCH v2] urlmon: Always report available data before stop_binding.

[Rémi Bernon]

On 1/4/22 23:23, Jacek Caban wrote:
> Hi Rémi,
> 
> On 1/4/22 21:31, Rémi Bernon wrote:
>> The HTML launcher of several Rebellion games (all probably based on the
>> same code) use a custom protocol handler which calls ReportResult in
>> LockRequest, causing an invalid memory access when OnDataAvailable
>> callback is called, as the binding has already been stopped and
>> terminated.
>>
>> Wine-Bug:https://bugs.winehq.org/show_bug.cgi?id=46213
>> Wine-Bug:https://bugs.winehq.org/show_bug.cgi?id=52286
>> Signed-off-by: Rémi Bernon<rbernon at codeweavers.com>
>> ---
>>
>> v2: Use an even more ad-hoc flag to detect LockRequest calls during
>>      ReportData.
>>
>>   dlls/mshtml/tests/htmldoc.c | 18 +++++++++++++++++-
>>   dlls/urlmon/binding.c       | 23 +++++++++++++++++++++++
>>   2 files changed, 40 insertions(+), 1 deletion(-)
> 
> 
> Those tests in htmldoc.c are a few layers above the problem, so they are 
> not very informative. I did a quick experiment (see the attachment) with 
> more precise test and an ad-hoc fix. It still needs better 
> understanding, but does it help in your case?
> 
> 
> Thanks,
> 
> Jacek

Hi Jacek,

I must admit that I have very little idea how all this urlmon thing 
works or does. Your patch only partially fix the launcher issue (it 
doesn't crash anymore but it still doesn't show any window).

As far as I understand, the custom protocol handler is:

1) Calling ReportResult within LockRequest.
2) Expecting OnDataAvailable to be called after.
3) Expecting OnStopBinding to be called after.

I believe your patch doesn't do 3)? I'm not sure it expects this to 
happen while ReportData is called, but it's how it usually happens, and 
it definitely expect OnStopBinding to be called after ReportResult has 
been, to continue.

It also causes ReportResult to return E_FAIL when called within 
LockRequest, which is not what native does (at least it's not with the 
mshtml version of the test).

Cheers,
-- 
Rémi Bernon <rbernon at codeweavers.com>