Whilst ‘whilst’ is nice, the sentence as it was before this change
indicated that the stack was in the call_pv call (whatever
that means).
The purpose of the macro C<SPAGAIN> is to refresh the local copy of the
stack pointer. This is necessary because it is possible that the memory
-allocated to the Perl stack has been reallocated whilst in the
+allocated to the Perl stack has been reallocated during the
I<call_pv> call.
If you are making use of the Perl stack pointer in your code you must