fix bug in NewmanInfinityCriterion trying to modify result of PCentra…

…lSeries
gap-system · Apr 8, 2016 · c8852da · c8852da
1 parent 5434201
commit c8852da
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/grpfp.gi b/lib/grpfp.gi
@@ -5242,7 +5242,7 @@ local GO,q,d,e,b,r,val,agemo,ngens;
     q:=PQuotient(G,p,2,ngens);
   until q<>fail;
   q:=Image(EpimorphismQuotientSystem(q));
-  q:=PCentralSeries(q,p);
+  q:=ShallowCopy(PCentralSeries(q,p));
   if Length(q)=1 then
     Error("Trivial <p> quotient");
   fi;