PriorityThreadPool didn't have very good error handling. If something
failed it would just ignore whatever was being processed. This could
lead to a query continuing without retreiving all of the required data.
This patch adds error handling, sending a message back to the client
and a log message. It also destroys and recreates the pool thread.
This fixes hex() so that it outputs the hex of the ASCII for the time
data to make it aligned with MariaDB. It also fixes the following
functions so that they use NOW() as a DATETIME with the input TIME added
to it:
* weekday()
* yearweek()
* monthname()
* last_day()
* year()
* weekofyear()
* week()
* to_days()
* quarter()
* month()
* dayofyear()
* dayofweek()
* dayofmonth()
* day()
* date()
If negative count number is more than the number of characters in the
string then it should always return the string.
For example if a table contains SUBSTRING_INDEX('zzz', 'z', -5) should
return 'zzz'. Before this patch it would return NULL.
StringStore originally worked by returning a 32bit pointer to a memory
location and storing the length with that pointer. This allowed 4GB to
be stored in 64KB blocks. With 1.1 we used the high bit to signify a
TEXT/BLOB string of > 64KB reducing the max capacity to 2GB but without
any bounds checking.
So, if you went over the 2GB mark the getter would think you are trying
to get a long string instead of a short one and come up empty. It would
then return NULL.
This patch uses 64bit memory points still retaining the high bit to
signify long strings. It also now stores the length with the string
rather than with the pointer to allow the full 64bits for pointers.
It also adds a bounds check for small strings.
Ubuntu 18.04 uses GCC 7.3 which is a little stricter than before.
Fixes a few errors due to implicit includes that are no longer implicit
and a ton of warnings about the implied alignment of code in
utils/common/any.hpp
