Re: chained transactions

Hello Peter,

> Attached is a rebased patch set.  No functionality changes.

Patch applies cleanly, compile, global make check ok, doc gen ok.

Shouldn't psql tab completion be updated as well?

About the code:

I must admit that do not like much the three global variables & 
Save/Restore functions. I'd suggest saving directly into 3 local variables 
in function CommitTransactionCommand, and restoring them when needed. Code 
should not be longer. I'd would not bother to skip saving when not 
chaining.

Copying & comparing nodes are updated. Should making, outing and reading 
nodes also be updated?

About the tests: I'd suggest to use more options on the different tests, 
eg SERIALIZABLE, READ ONLY… Also ISTM that tests should show 
transaction_read_only value as well.

-- 
Fabien.