1f39a1c064
Originally, if libpq got a failure (e.g., ECONNRESET) while trying to send data to the server, it would just report that and wash its hands of the matter. It was soon found that that wasn't a very pleasant way of coping with server-initiated disconnections, so we introduced a hack (pqHandleSendFailure) in the code that sends queries to make it peek ahead for server error reports before reporting the send failure. It now emerges that related cases can occur during connection setup; in particular, as of TLS 1.3 it's unsafe to assume that SSL connection failures will be reported by SSL_connect rather than during our first send attempt. We could have fixed that in a hacky way by applying pqHandleSendFailure after a startup packet send failure, but (a) pqHandleSendFailure explicitly disclaims suitability for use in any state except query startup, and (b) the problem still potentially exists for other send attempts in libpq. Instead, let's fix this in a more general fashion by eliminating pqHandleSendFailure altogether, and instead arranging to postpone all reports of send failures in libpq until after we've made an attempt to read and process server messages. The send failure won't be reported at all if we find a server message or detect input EOF. (Note: this removes one of the reasons why libpq typically overwrites, rather than appending to, conn->errorMessage: pqHandleSendFailure needed that behavior so that the send failure report would be replaced if we got a server message or read failure report. Eventually I'd like to get rid of that overwrite behavior altogether, but today is not that day. For the moment, pqSendSome is assuming that its callees will overwrite not append to conn->errorMessage.) Possibly this change should get back-patched someday; but it needs testing first, so let's not consider that till after v12 beta. Discussion: https://postgr.es/m/CAEepm=2n6Nv+5tFfe8YnkUm1fXgvxR0Mm1FoD+QKG-vLNGLyKg@mail.gmail.com
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.