One of the conditions for non-blocking PQconnectStart and PQconnectPoll is "The hostaddr and host parameters are used appropriately to ensure that name and reverse name queries are not made". We overlook this condition.

(This is not same as the MultiClientConnectStart item which is done. We are overlooking the quoted doc condition, which hasn't caused us problems until now) One of the conditions so that PQconnectStart and PQconnectPoll don't block is "The hostaddr and host parameters are used appropriately to ensure that name and reverse name queries are not made". We currently overlook this condition, and should look into it in more detail.

Start with the PQconnectStart and PQconnectPoll call paths and compare their hostaddr and host handling with PostgreSQL's quoted non-blocking condition. Determine where name and reverse name queries can occur and define the expected non-blocking behavior; the issue does not name specific files or tests.

Written by the indexing model from the issue text.