Hi all, A connection with only a hostaddr (no host) can't be cancelled via PQcreateCancel(), because we'll crash in emitHostIdentityInfo(). The problem is that the synthetic connhost entry we've created for cancellation has an incorrect type field, which causes the following code to make bad decisions if connhost[0].host is NULL:
> emitHostIdentifyInfo(...)
> {
> ...
> if (conn->connhost[conn->whichhost].type == CHT_HOST_ADDRESS)
> displayed_host = conn->connhost[conn->whichhost].hostaddr;
> else
> displayed_host = conn->connhost[conn->whichhost].host;
> ...
> if (conn->connhost[conn->whichhost].type != CHT_HOST_ADDRESS &&
> host_addr[0] &&
> strcmp(displayed_host, host_addr) != 0) <- crashes here
I think the solution is just to copy over the correct type, as done in
the attached 0001.
Putting in a regression test requires us to once again answer the
question of "where do we test TCP-only features". I'd like to have a
PG_TEST_EXTRA entry for these, so 0002 adds a `tcp` group. That's
going to need more debate, and 002_tcp.pl is very quick-and-dirty, but
I also _really_ want to stop throwing tests away just because we don't
have a nice place to put them... [1]
So: if 0001 looks good, I propose that I backpatch it after beta1, but
hold onto 0002 until REL_18_STABLE is split off. Then we can figure
out the "test TCP" semantics for the full 19 cycle, and maybe
eventually backpatch tests once we're happy with how they work.
WDYT?
--Jacob
[1]
https://postgr.es/m/flat/CAOYmi%2Bkx8eOmKj01dV4vSBeq9pvqR8dt6rGw%2BB_pBOE2_GOj%2Bg%40mail.gmail.com
v1-0001-Fix-connhost-type-during-non-blocking-cancellatio.patch
Description: Binary data
v1-0002-WIP-add-TCP-tests.patch
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