some MTR tests fail with --ssl

When MTR runs with --ssl (as Fedora's %check does), all client connections use TLS. This causes four categories of test failure. All fixes are test-side, backward-compatible, and produce identical results without --ssl.

PR: https://github.com/MariaDB/server/pull/4929

1. TLS error codes replace MySQL protocol error codes

The connector's TLS layer intercepts server-side errors before the MySQL protocol can report them. For example, error 2026 (CR_SSL_CONNECTION_ERROR) replaces 2013 (CR_SERVER_LOST) on killed/crashed connections, and error 2002 (CR_CONNECTION_ERROR) replaces 1040 (ER_CON_COUNT_ERROR) when max_connections is exceeded.

This was partially addressed in two earlier commits (CONC-603 in 2022, MDEV-30452 in 2023), but only for tests actively failing upstream at the time. Thirteen tests remained unfixed.

This is arguably a connector bug — the connector should propagate the server's error code through the TLS layer rather than replacing it with a generic TLS error. The test-side fix (adding the TLS error codes to --error directives) is needed until the connector is fixed, and becomes a harmless no-op afterward.

2. Value differences in test output

connection_type in performance_schema.threads shows 'SSL/TLS' instead of 'Socket'. The server_audit plugin logs the TLS version (e.g. 'TLSv1.3') in CONNECT/DISCONNECT events.

Fix: --replace_result and --replace_regex to normalize the output. Without --ssl the replacements are no-ops.

3. Missing PFS socket instrumentation

Under TLS, data flows through SSL_read/SSL_write instead of direct recv/send syscalls, completely bypassing the performance_schema socket I/O instrumentation hooks. Tests that verify socket wait events or byte counters get zero values.

Fix: detect active TLS session via Ssl_cipher status variable and skip the affected tests. The existing not_ssl.inc checks @@have_ssl (server capability), which is always 'YES' on OpenSSL builds and would skip too aggressively.

4. Ssl_cipher_list truncation

Ssl_cipher_list contains the full list of supported ciphers (~2047 chars on Fedora's OpenSSL 3.x), exceeding the VARCHAR(1024) VARIABLE_VALUE column in PFS and information_schema tables. This causes ER_DATA_TOO_LONG in multi-table UPDATEs with STRICT_TRANS_TABLES, and Warning 1265 in information_schema SELECTs.

Fix: temporarily relax sql_mode for PFS-joining UPDATEs; wrap information_schema SELECTs with --disable_warnings.

—

Upstream CI doesn't use --ssl, so these failures go unnoticed.