* `get_master_version_and_clock()` de-duplicate label using fall-through
* `io_slave_killed()` & `check_io_slave_killed()`:
* reüse the result from the level lower
* add distinguishing docs
* `try_to_reconnect()`: extract `'` from `if`-`else`
* `handle_slave_io()`: Both `while`s have the same condition;
looks like the outer `while` can simply be an `if`.
* `connect_to_master()`:
* assume `mysql_errno()` is not 0 on connection error
* utilize 0’s falsiness in the loop
* extend docs
* `sql/sql_show.cc`: refactor SHOW ALL REPLICAS filter’s condition
* `sql/mysqld.cc`: init `master-retry-count` with `master_retry_count`
Reviewed-by: Kristian Nielsen <knielsen@knielsen-hq.org>
When the IO thread (re)connect to a primary,
no updates are available besides unique errors that cause the failure.
These new `Master_info` numbers supplement SHOW SLAVE STATUS’s (most-
recent) ‘Connecting’ state with statistics on (re)connect attempts:
* `Connects_Tried`: how many retries have been attempted so far
This was previously a local variable that only counted re-attempts;
it’s now meaningful even after the “Connecting” state concludes.
* `Master_Retry_Count` (from MDEV-25674): out of how many configured
Side-note: Some of the tests updated by this commit dump the entire
SHOW SLAVE STATUS, which might include non-deterministic entries.
Reviewed-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Reviewed-by: Brandon Nesterenko <brandon.nesterenko@mariadb.com>
