Thread: pgsql: Cope with a deficiency in OpenSSL 3.x's error reporting.

Cope with a deficiency in OpenSSL 3.x's error reporting.

In OpenSSL 3.0.0 and later, ERR_reason_error_string randomly refuses
to provide a string for error codes representing system errno values
(e.g., "No such file or directory").  There is a poorly-documented way
to extract the errno from the SSL error code in this case, so do that
and apply strerror, rather than falling back to reporting the error
code's numeric value as we were previously doing.

Problem reported by David Zhang, although this is not his proposed
patch; it's instead based on a suggestion from Heikki Linnakangas.
Back-patch to all supported branches, since any of them are likely
to be used with recent OpenSSL.

Discussion: https://postgr.es/m/b6fb018b-f05c-4afd-abd3-318c649faf18@highgo.ca

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/453c46873774219243501b8efc16b2b5a5e9d194

Modified Files
--------------
src/backend/libpq/be-secure-openssl.c    | 19 ++++++++++++++++---
src/interfaces/libpq/fe-secure-openssl.c | 23 ++++++++++++++++++++---
2 files changed, 36 insertions(+), 6 deletions(-)