Looking at memread in http://cpansearch.perl.org/src/MHX/IPC-SysV-2.03/SysV.xs, my guess is that the IV field of the variable remains untouched when reading/writing the string portion of the shared memory:

...
    SvPV_force_nolen(sv);
    dst = SvGROW(sv, (STRLEN) size + 1);
    Copy(caddr + pos, dst, size, char);
    SvCUR_set(sv, size);
...

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(assuming that none of the macros actually reset the IV slot). I think this could be construed as a bug.

In reply to Re^2: Is this a bug in perl or a bug in me? by Corion
in thread Is this a bug in perl or a bug in me? by Wheely

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