polycyclic: IsConjugate for pcp groups returns element instead of boolean

[ThGroth]

Observed behaviour

As verified in the code the method IsConjugate for polycyclic groups (pkg/polycyclic-2.11/gap/pcpgrp/centcon.gi:328) returns not a boolean but in some cases the conjugator.
For example:

H := DihedralPcpGroup( 0 );
IsConjugate(H,One(H),One(H));

returns "id" instead of "true"

Perhaps the method should be changed to

 InstallMethod( IsConjugate, "for a pcp group", IsCollsElmsElms, [IsPcpGroup, IsPcpElement, IsPcpElement],
      function( G, g, h )
           return not false = ConjugacyElementsBySeries( G, g, h, PcpsOfEfaSeries(G) );
 end );

GAP 4.8.3, 19-Mar-2016, build of 2016-04-20 10:15:48 (CEST)
Architecture: x86_64-pc-linux-gnu-gcc-default64

[markuspf]

While this is a bug, and the fix seems to be the correct one, this is a bug in the polycyclic package. @fingolfin would you be able to fix this?

[fingolfin]

Yes, this should get fixed in polycyclic. Ahh, I wish I had a public bug tracker for that.. Gotta talk to Bettina about this

[olexandr-konovalov]

This issue is migrated to gap-packages/polycyclic#18. Thank you @ThGroth for reporting it.