• Davi Arnaut's avatar
    Bug#41110: crash with handler command when used concurrently with alter table · 322a5a39
    Davi Arnaut authored
    Bug#41112: crash in mysql_ha_close_table/get_lock_data with alter table
    
    The problem is that the server wasn't handling robustly failures
    to re-open a table during a HANDLER .. READ statement. If the
    table needed to be re-opened due to it's storage engine being
    altered to one that doesn't support HANDLER, a reference (dangling
    pointer) to a closed table could be left in place and accessed in
    later attempts to fetch from the table using the handler. Also,
    if the server failed to set a error message if the re-open
    failed. These problems could lead to server crashes or hangs.
    
    The solution is to remove any references to a closed table and
    to set a error if reopening a table during a HANDLER .. READ
    statement fails.
    
    There is no test case in this change set as the test depends on
    a testing feature only available on 5.1 and later.
    322a5a39
sql_handler.cc 24 KB