Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw

Re^4: ref to read-only alias ... why? (notabug)

by dk (Chaplain)
on Jan 06, 2012 at 17:46 UTC ( #946636=note: print w/replies, xml ) Need Help??

in reply to Re^3: ref to read-only alias ... why? (not consistent)
in thread ref to read-only alias ... why?

Heh, it's a 8-year old (!!!!) bug: . With resolution that it's indeed a bug ... well, that situation doesn't seem good to me, when noone wants to touch a bug in 8 years. I wonder why.
  • Comment on Re^4: ref to read-only alias ... why? (notabug)

Replies are listed 'Best First'.
Re^5: ref to read-only alias ... why? (notabug)
by LanX (Chancellor) on Jan 06, 2012 at 17:49 UTC
    Thats what I expected.

    > I wonder why.

    IMHO legacy code would break if you die here.

    But a warning would be great.

    Cheers Rolf

      I agree on a warning, it would be a practical thing, after all. And after that, a real fix with 'die' a couple versions later should help the legacy code.

      Well anyway, I found the code suggested by ikegami, so would you guys review the patch please?

      --- pp.c.0 2012-01-06 01:07:34.511988700 +0100 +++ pp.c 2012-01-06 19:04:06.311428300 +0100 @@ -515,9 +515,11 @@ SvTEMP_off(sv); SvREFCNT_inc_void_NN(sv); } - else if (SvPADTMP(sv) && !IS_PADGV(sv)) + else if (SvPADTMP(sv) && !IS_PADGV(sv)) { + Perl_ck_warner(aTHX_ packWARN(WARN_MISC), + "Implicit copy of a read-only scalar due to aliasing"); sv = newSVsv(sv); - else { + } else { SvTEMP_off(sv); SvREFCNT_inc_void_NN(sv); }

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://946636]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others taking refuge in the Monastery: (11)
As of 2016-10-24 16:32 GMT
Find Nodes?
    Voting Booth?
    How many different varieties (color, size, etc) of socks do you have in your sock drawer?

    Results (309 votes). Check out past polls.