Re: [bug fix] Cascaded standby cannot start after a clean shutdown

On Sun, Mar 18, 2018 at 08:49:01AM +0900, Michael Paquier wrote:
> On Fri, Mar 16, 2018 at 06:02:25AM +0000, Tsunakawa, Takayuki wrote:
>> Ouch, you're right.  If memory allocation fails, the startup process
>> would emit a LOG message and continue to fetch new WAL records.  Then,
>> I'm completely happy with your patch.
> 
> Thanks for double-checking, Tsunakawa-san.

As this is one of those small bug fixes for which we can do something,
attached is an updated patch with a commit description, and
tutti-quanti.  At the end, I have moved the size check within
allocate_recordbuf().  Even if the size calculated is not going to be
higher than total_len, it feels safer in the long term for two reasons:
- Allocation size calculation could be changed, or let's say made
smarter.
- New callers of allocate_recordbuf would not be able to see the problem
for the backend, and this could become a problem if the WAL reader
facility is extended.

Thoughts?
--
Michael