From: Thomas Rast Date: Tue, 16 Jul 2013 09:25:34 GMT Subject: Re: [PATCH 0/2] open() error checking Message-ID: <87hafukga9.fsf@linux-k42r.v.cablecom.net> In-Reply-To: <7vtxjzlmaf.fsf@alter.siamese.dyndns.org> Junio C Hamano writes: > Thomas Rast writes: > >> I originally had a four-patch series to open 0/1/2 from /dev/null, but >> then I noticed that this was shot down in 2008: >> >> http://thread.gmane.org/gmane.comp.version-control.git/93605/focus=93896 > > The way I recall the thread was not "shot down" but more like > "fizzled out without seeing a clear consensus". As a normal POSIX > program, we do rely on fd#2 connected to an error stream, and I do > agree with the general sentiment of that old thread that it is very > wrong for warning() or die() to write to a pipe or file descriptor > we opened for some other purpose, corrupting the destination. > > I briefly wondered if we can do the sanity check lazily (e.g. upon > first warning() see of fd#2 is open and otherwise die silently), but > we may open a fd (e.g. to create a new loose object) that may happen > to grab fd#2 and then it is too late for us to do anything about it, > so... I think we'd have to do it on startup. Since we do many things already, a few extra dup calls should hardly matter. I'll send the patches in reply in a minute, I had them lying around already. But if you (again) decide that it's not worth it, I don't care too deeply. -- Thomas Rast trast@{inf,student}.ethz.ch