• Marko Mäkelä's avatar
    Bug#17312846 CHECK TABLE ASSERTION FAILURE · 55129f67
    Marko Mäkelä authored
    DICT_TABLE_GET_FORMAT(CLUST_INDEX->TABLE) >= 1
    
    The function row_sel_sec_rec_is_for_clust_rec() was incorrectly
    preparing to compare a NULL column prefix in a secondary index with a
    non-NULL column in a clustered index.
    
    This can trigger an assertion failure in 5.1 plugin and later. In the
    built-in InnoDB of MySQL 5.1 and earlier, we would apparently only do
    some extra work, by trimming the clustered index field for the
    comparison.
    
    The code might actually have worked properly apart from this debug
    assertion failure. It is merely doing some extra work in fetching a
    BLOB column, and then comparing it to NULL (which would return the
    same result, no matter what the BLOB contents is).
    
    While the test case involves CHECK TABLE, this could theoretically
    occur during any read that uses a secondary index on a column prefix
    of a column that can be NULL.
    
    rb#3101 approved by Mattias Jonsson
    55129f67
row0sel.c 132 KB