View definition as SELECT ... FROM DUAL WHERE ... has
valid syntax, but use of such view in SELECT or
SHOW CREATE VIEW syntax causes unexpected syntax error.
Server omits FROM DUAL clause when storing view body
string in a .frm file for further evaluation.
However, syntax of SELECT-witout-FROM query is more
restrictive than SELECT FROM DUAL syntax, and doesn't
allow the WHERE clause.
NOTE: this syntax difference is not documented.
View registration procedure has been modified to
preserve original structure of view's body.
The bug is a regression introduced in 5.1 by the patch for bug28404.
Under some circumstances test_if_skip_sort_order() could leave some
data structures in an inconsistent state so that some parts of code
could assume the selected execution strategy for GROUP BY/DISTINCT as
a loose index scan (e.g. JOIN_TAB::is_using_loose_index_scan()), while
the actual strategy chosen was an ordered index scan, which led to
wrong data being returned.
Fixed test_if_skip_sort_order() so that when changing the type for a
join table, select->quick is reset not only for EXPLAIN, but for the
actual join execution as well, to not confuse code that depends on its
value to determine the chosen GROUP BY/DISTINCT strategy.
plugin_load.test created lines in the warnings files and made
pushbuild cells yellow. Some pushbuild systems are configured
so that they don't build the ha_example plugin. Trying to load
them creates error messages in the error log. These were copied
to the warnings file.
Fixed by ignoring expected error messages for non-existent
ha_example.
When trying to get the requested amount of memory for the keybuffer,
the out of memory could be signaled if one of the tentative allocations
fail. Later the server would crash (debug assert) when trying to send
a ok packet with a error set.
The solution is only to signal the error if all tentative allocations
for the keybuffer fail.
The server used to trust blindly information from the client about
its capabilities. During the connection handshake the server sends
information about what it supports and then the client sends back a
set of capabilities which cover all of the server's or less.
Before this changeset the server didn't check whether the flags sent
by the client were valid for the server. For example, if the server
doesn't support compressed protocol but the client does and sends that
bit turned on, the server didn't check it. The change make the server code
less error prone to problems related to the value of THD::client_capabilities.
Clearly there is no vulnerability being fixed but this is a maintainenance
fix to prevent misusage in the future.
