WMSyncReader starts a background read thread that reads from the IStream
passed to IWMSyncReader::OpenStream. This means it could use the IStream in the
background even when no IWMSyncReader methods are being called.
For well-behaved applications, this is probably OK. However, AQUARIUM
(Steam 2515070) frees the IStream it passes to WMSyncReader _before_
it calls IWMSyncReader::Close, which stops the read thread. This causes
the read thread to access freed memory. This is improper, but not
unreasonable, as IWMSyncReader is supposed to be a synchronous
interface, so one might assume when they weren't calling into
IWMSyncReader methods, the IStream won't be used.
This commit adds a `wg_parser_dont_read` function, which can be used to
stop wg_parser from issuing read requests. This is used by IWMSyncReader
to make sure read requests are only issued when IWMSyncReader methods
are being called.
--
v2: winegstreamer: Make sure WMSyncReader never reads in the background.
https://gitlab.winehq.org/wine/wine/-/merge_requests/7676