Bug #25372 for Devel-PPPort: special case sv_magic(sv, obj, how, name, 0)

First of all, I'd like to apologize for this reply coming so late. But somehow your message didn't make it into my inbox and I just found it by accident when I logged into RT today. As for sv_magic(), I don't think that this can be easily, if at all, done by Devel::PPPort. There are several problems: 1. The change in behaviour is about *not* doing something, not about doing something extra. This means it cannot be done by wrapping sv_magic() in a macro or something like that, it would have to be done by re-implementing sv_magic() in ppport.h. This is ugly, but certainly doable. 2. The real problem is that by the time sv_unmagic() is called, older perls will always attempt to Safefree() the mg_ptr, whether it's a copy or not. And this behaviour cannot be influenced by Devel::PPPort. So, unless I'm completely wrong [*], this problem cannot be solved by Devel::PPPort. You have to take care in the XS code, or just drop support for pre-5.8 perls. Sorry for the bad news, Marcus [*] In that case, please let me know! :-)

Hi, Show quoted text
It is not very elegant, but I think that setting mg->mg_len = -1 will do: #define my_sv_magic(sv, obj, how, name, namelen) if (!name || namelen != 0) sv_magic(sv, obj, how, name, namelen else { sv_magic(sv, obj, how, 0, 0); mg = ...; mg->mg_len = -1; mg->mg_ptr = name; } Or at least, a warning could be printed: #define my_sv_magic(sv, obj, how, name, namelen) if ((name) && !(namelen)) Perl_warn("..."); sv_magic(sv, obj, how, name, namelen);