The following review has been posted through the commitfest application:
make installcheck-world: tested, passed
Implements feature: not tested
Spec compliant: not tested
Documentation: not tested
The patch looks good to me. With regards to the code comments, I had pretty similar concerns as already raised by Dmitry; and those have already been answered by you. So this patch is good to go from my side once you have updated the comments per your last email.