develooper Front page | perl.perl5.porters | Postings from March 2020

Re: [Perl/perl5] fb8188: fixup to "avoid identical stack traces"

From:
Dave Mitchell
Date:
March 18, 2020 14:13
Subject:
Re: [Perl/perl5] fb8188: fixup to "avoid identical stack traces"
Message ID:
20200318141318.GB4082@iabyn.com
On Fri, Mar 13, 2020 at 08:02:32AM +0000, Steve Hay via perl5-porters wrote:
> On Thu, 12 Mar 2020 at 15:29, iabyn <noreply@github.com> wrote:
> 
> >   Branch: refs/heads/blead
> >   Home:   https://github.com/Perl/perl5
> >   Commit: fb8188b84d8a8f34f90aa9a8d9837892967f6b93
> >
> > https://github.com/Perl/perl5/commit/fb8188b84d8a8f34f90aa9a8d9837892967f6b93
> >   Author: David Mitchell <davem@iabyn.com>
> >   Date:   2020-03-12 (Thu, 12 Mar 2020)
> >
> >   Changed paths:
> >     M MANIFEST
> >     M op.c
> >     A t/lib/GH_15109/Foo.pm
> >     M t/op/caller.t
> >
> >   Log Message:
> >   -----------
> >   fixup to "avoid identical stack traces"
> >
> > GH #15109, #17567
> >
> > My original fix for this issue, v5.31.6-141-gf2f32cd638
> > made a shallow copy of &PL_compiling. However, for non-default
> > warning bits, this made two COPs share the malloced() cop_warnings,
> > and bad things ensured. In particular this was flagged up in:
> >
> >     GH #17567: "BBC: AYOUNG/OpenVZ-0.01.tar.gz"
> >
> > The fix in this commit is to do a deep copy of the COP using
> > newSTATEOP().
> >
> 
> Does this spell trouble for the expected release of 5.30.2 tomorrow, given
> that  v5.31.6-141-gf2f32cd638 has been backported to it?
> 
> I saw one problem regarding that change in
> https://rt.cpan.org/Public/Bug/Display.html?id=132080 but I think that just
> requires a fix in the module in question to account for the change, as I
> commented on that ticket.
> 
> But this new problem is more worrying if it requires a fix in the core,
> especially since the fix mentioned above has since been reverted.
> 
> I'm inclined to revert the backport of f2f32cd638 in maint-5.30 rather than
> hold up 5.30.2 for a new fix and allow time for smoking it.
> 
> If there is a well-smoked fix available soonish then it might be able to go
> into 5.30.3, which is due fairly soon for some security issues, or
> otherwise will have to wait for 5.30.4.

Sorry for not getting back to you sooner. Yes, reverting was the right
thing. My gut feeling is that it should NOT be applied to any maint
release: too much chance of breakage, since although it fixes broken
behaviour, it's been like that forever.

-- 
The optimist believes that he lives in the best of all possible worlds.
As does the pessimist.



nntp.perl.org: Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at ask@perl.org | Group listing | About