[PATCH v2 0/1] MR3390: ntdll: Correctly handle pread short reads

[Aidan Hobson Sayers (＠aidanhs)]

The read and pread syscalls are permitted to return fewer bytes than requested (unlike the fread libc call which will only perform a short read on error or EOF). This is most likely to occur when binaries are located on slower filesystems (e.g. NFS or 9pfs)

ffab9d9 is a relatively recent regression here, but a lot of the code appears to be much older (e.g. the read call in 341b7dc)

In this MR I've focused on ntdll, but I see a lot of similar mishandling of the pread return value in `server/`. I will raise a bug as I don't intend to create a follow up MR at this time.

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  v2: ntdll: Correctly handle pread short reads
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/3390