So the fix takes the perspective that the
implementation of [info frame] failed to
account for an unusual, but normal condition.

This is in contrast to a perspective that
(corPtr->caller.cmdFramePtr == NULL) was
an invalid state and some bug was wrongly
allowing it to occur.

Accepting that, we should merge the fix to
the trunk.

Any prospects for crafting a test for the
test suite that doesn't require a 2100 line
script?