Subject: Re: bug#17172: 24.3.50; Timeouts when pasting from mouse

From: Jan Djärv <[email-masked]>
Date: Tue, 15 Apr 2014 22:41:23 +0200

Hello. 

> 15 apr 2014 kl. 22:19 skrev Paul Eggert <[email-masked]>:
> 
> Jan Djärv wrote:
>> That can't happen, all masks are initialized with FD_ZERO.
> 
> True, but after that they can be reused in some cases and it's not immediately obvious that they are guaranteed to be properly reinitialized for every call to xg_select.

They are not reinitialized with FD_ZERO, but no garbage bits are ever set. 

> 
>> If we passed masks with garbage in them to pselect we would get EINVAL back.
> 
> Not if the garbage's 1 bits happen to correspond to open file descriptors.

But there are no garbage bits.

> 
>> In that case, process.c does not inspect the masks, so this change fixes nothing.
> 
> Although it doesn't inspect the masks right away, in some cases it reuses a mask later.  The code is reasonably tricky here.

Not so you can't follow it. 

> 
>> you just used it as a means to get untested code into the emacs-24 branch
> 
> Hmm, well, that's a bit unfair as I did test it, but as you're sure the change doesn't fix any user-visible bugs I reverted it.

It was not tested by the OP of this bug. 

     Jan D.