RE: Logical replication timeout problem

Dear Wang,

Thank you for updating!

> > Do we need adding a test for them? I think it can be added to 100_bugs.pl.
> > Actually I tried to send PoC, but it does not finish to implement that.
> > I'll send if it is done.
> I'm not sure if it is worth it.
> Because the reproduced test of this bug might take some time and might risk
> making the build farm slow, so I am not sure if others would like the
> reproduced test of this bug.

I was taught from you that it may suggest that it is difficult to stabilize and
minimize the test. I withdraw the above.
I put some comments for v2, mainly cosmetic ones.

1. pgoutput_change
```
+       bool is_send = true;
```

My first impression is that is_send should be initialized to false,
and it will change to true when OutputPluginWrite() is called.


2. pgoutput_change
```
+                               {
+                                       is_send = false;
+                                       break;
+                               }
```

Here are too many indents, but I think they should be removed.
See above comment.

3. WalSndUpdateProgress
```
+               /*
+                * If half of wal_sender_timeout has lapsed without send message standby,
+                * send a keep-alive message to the standby.
+                */
```

The comment seems inconsistency with others.
Here is "keep-alive", but other parts are "keepalive".

4. ReorderBufferProcessTXN
```
+
change->data.inval.ninvalidations,
+
change->data.inval.invalidations);
```

Maybe these lines break 80-columns rule.

Best Regards,
Hayato Kuroda
FUJITSU LIMITED