Re: [Qemu-devel] [PATCH 08/18] migration (outgoing): add error propagation for fd and exec protocols

[Paolo Bonzini]

Il 05/10/2012 14:41, Luiz Capitulino ha scritto:
>>> > > That DPRINTF() usage is really bizarre, it seems its purpose is to 
>>> > > report
>>> > > an error to the user, but that's a debugging call.
>>> > > 
>>> > > I'd let it there and replace it later with proper tracing code, but 
>>> > > that's
>>> > > quite minor for me. Please, at least mention you're dropping it in the 
>>> > > log.
>> > 
>> > This one is not dropped, it becomes the reported error message.
> What I meant is that the error/debug message won't be printed the same way
> it was before. This is an improvement, but it's a good idea to mention it.
> 

I mentioned it for fd, but the popen() function only returns NULL if the
fork(2) or pipe(2) calls fail, or if it cannot allocate memory, so I
have no idea how to trigger it.

>> It would also fix the clobbering of errno.
> 
> I guess so. Is it possible for popen() to return success but then set the
> FILE's fd to -1?

No.  I will add the assert().

Paolo