Re: [perl #75758] Perl print error to STDERR, but finish with error status 0

On Wed, Jun 16, 2010 at 01:16:08PM +0100, Nicholas Clark wrote:
> On Tue, Jun 15, 2010 at 03:00:08AM -0700, Alex Varyanick wrote:
> 
> Thanks for the report.
> > This code:
> > perl -e'\sort{eval$;}%!' && echo "exit 0"
> > prints: "panic: restartop" into STDERR and finish with exit status 0
> 
> That turns out to already be fixed in blead. I bisected with
> 
> #!/bin/sh
> git clean -dxf
> # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
> # if Encode is not needed for the test, you can speed up the bisect by
> # excluding it from the runs with -Dnoextensions=Encode
> sh Configure -des -Dusedevel -Uusethreads -Doptimize="-Os" -Dcc=ccache\ gcc -Dld=gcc -Dnoextensions=Encode
> test -f config.sh || exit 125
> # Correct makefile for newer GNU gcc
> perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
> # if you just need miniperl, replace test_prep with miniperl
> make -j4 test_prep
> [ -x ./perl ] || exit 125
> ./perl -Ilib -e'\sort{eval$;}%!' 2>&1 | grep panic
> ret=$?
> [ $ret -gt 127 ] && ret=127
> git clean -dxf
> 
> and it reveals that the fix was
> 
> 27e904532594b7fb224bdf9a05bf3b5336b8a39e is first bad commit
> commit 27e904532594b7fb224bdf9a05bf3b5336b8a39e
> Author: David Mitchell <[email protected]>
> Date:   Thu Apr 8 13:16:56 2010 +0100
> 
>     fix RT 23810: eval and tied methods
>     
>     Something like the following ended up corrupted:
>         sub FETCH { eval 'BEGIN{syntax err}' }
>     The croak on error popped back the context stack etc to the EVAL pushed by
>     entereval, but the corresponding JUMPENV_PUSH(3) unwound all the way to the
>     outer perl_run, losing all the mg_get() related parts of the C stack.
>     
>     It turns out that the run-time parts of pp_entereval were protected with
>     a new JUMPENV level, but the compile-time parts weren't. Add this.
> 
> :100644 100644 80c7b221d7e967a6f3380d70917bd73700b16852 bbb2d1587cb197977c996ecfe8abddf4f9aa3631 M      pp_ctl.c
> :040000 040000 7fa8480b6084b533c3eaddbbbd6834e2551f8a4e f2ec8022695df42cff76ab78c117bd44d1fb626c M      t
> bisect run success
> 
> I don't have a 5.12 handy, but I think from the timing that that fix isn't
> in 5.12

Indeed, it still is an issue in 5.12.1.

> > This code:
> > perl -e'/(?{"})/' && echo "exit 0"
> > prints: "panic: top_env" into STDERR and finish with exit status 0
> 
> This is still a bug in blead.

Some additional diagnostic:

  $ perl -e'/(?{"})/'
  panic: top_env
  perl: perl.c:542: perl_destruct: Assertion `PL_scopestack_ix == 1' failed.
  Aborted
  $


which is exactly the same error "perl -e'\sort{eval$;}%!'" gives me in 5.12.1.


Abigail