Deadlocks in nested stored procedures are not propagating the deadlock error back to the application properly when using Connector/ODBC.
Attached is an ODBC Trace when calling a SP. You can see that the call to NextResult() returned SQL_NO_DATA_FOUND, and not the error.
And per Georg:
"Afaik the problem is here: https://github.com/MariaDB/mariadb-connector-odbc/blob/master/ma_result.c#L95
if mysql_stmt_next_result failed, the function should return an error. SQL_NO_DATA is ok, if field_count is zero"