Re: "q" with psql display paging dumps out of psql

jseymour(at)linxnet(dot)com (Jim Seymour) writes:
> I recently upgraded from 7.4.2 to 7.4.6 and have run into a new
> problem. As frequently as not, maybe even most times, when I "q" out
> of paging the output of a query in psql: Instead of just quitting that
> query, I get dumped straight out of psql. To add insult to injury: The
> command history for the current session isn't saved.
> "echo $?" after it happens yields "141."

141-128 = 13 = SIGPIPE. So psql is getting sigpipe'd. The question is
why? It is set up to ignore SIGPIPE everywhere that it could reasonably
expect to get it, in particular from writing to the pager.

> I'm guessing it's some kind of race condition.

The timing condition involved is probably whether or not psql has
finished writing all of the query result to the pager before you
quit the pager. So if you retrieve a large query result and "q"
immediately you can probably make it more reproducible.

Also, I don't think we changed that stuff between 7.4.2 and 7.4.6
(though I haven't trawled the commit logs to make sure). Was your
7.4.2 installation also built with --enable-thread-safety? It seems
likely that addition or removal of --enable-thread-safety would make
a difference.

regards, tom lane