The task is completed in the bb-10.2-spider-jacob branch, waiting to be merged into the 10.2-spider branch after Monty has finished his Spider patch integration work.

Pushed into bb-10.3-monty. Will be pushed to 10.3 soon with the rest of the patches in this tree.

Here is the commit message:

MDEV-7722 Add new variable log_result_errors

• MDEV-772 originally named as spider patch
  024_mariadb-10.2.0.log_result_errors.diff
• log_result_errors allows one to log warnings and errors to the error log
• This patch has the following differences compared to the original patch:
• Fixed output to be compatible with rest of error log
• Simplified code (removed duplicate code)
• Added mutex protection
• Added test case
• Only allow levels 0-3 (level 4, printing of information for every
  result is not that useful and would fill up error log quickly).

After talking with Sergei, we concluded that we will not take this patch as we have in 10.1 the sql_error_log plugin
that already handles some of the cases of the log_result_error variable. We plan to extend this to also log warnings and notes.

See https://mariadb.com/kb/en/mariadb/sql_error_log-plugin/

MDEV-7389 will replace this task

Will not apply