grants are reapplied.
After renaming a user and trying to re-apply grants results in additional
grants.
This is because we use username as part of the key for GRANT_TABLE structure.
When the user is renamed, we only change the username stored and the hash key
still contains the old user name and this results in the extra privileges
Fixed by rebuilding the hash key and updating the column_priv_hash structure
when the user is renamed
for wildcard values.
The server ignored escape character before wildcards during
the calculation of priority values for sorting of a privilege
list. (Actually the server counted an escape character as an
ordinary wildcard like % or _). I.e. the table name template
with a wildcard character like 'tbl_1' had higher priority in
a privilege list than concrete table name without wildcards
like 'tbl\_1', and some privileges of 'tbl\_1' was hidden
by privileges for 'tbl_1'.
The get_sort function has been modified to ignore escaped
wildcards as usual.
clean up SHOW GRANTS so it will show host-names with case as entered.
make REVOKE and friends case-sensitive to make things more intuitive.
Patch by Martin Friebe.
