[MPlayer-dev-eng] [PATCH] x11_common: XChangeProperty uses long for 32-bits

[Nicolas George]

Le decadi 30 thermidor, an CCXIX, Alexander Strasser a écrit :
>   Of course! Good catch. It is always the simplest things, that can go
> awfully wrong. Thank you for having a close look.
> 
>   Looking at my comment again, we are not checking if the PID fits into
> 32 bits, I guess this way it might happen that the X server receives a
> partial PID. Could we use a bitwise AND operation to only assign bits
> 0 to 31, so that we do the early return when pid contains a value that
> doesn't fit into 32 bits? That approach might fail on sign extension
> of a negative value of a signed 32-bit pid_t into a signed 64 bit long
> type in some cases. But I would like to think that is more hypothetical.

A process ID is positive, while pid_t is signed: using a binary AND to mask
only bits 0 to 30 (and not 31) should be safe.

In the meantime, I could test the code on an UltraSparc in the GCC Compile
Farm: the current code dies with a SIGBUS, the modified code works and sets
_NET_WM_PID correctly. Here is the updated patch.

If there is no further remarks, I can push any time.

Regards,

-- 
  Nicolas George
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