If we compare two items A and B, with B being (a constant) of a
larger type, then A gets promoted to B's type for comparison if
it's a constant, function, or CAST() column, but B gets demoted
to A's type if A is a (not explicitly CAST()) column. This is
counter-intuitive and not mandated by the standard.
Disabling optimisation where it would be lossy so field value
will properly get promoted and compared as binary string (rather
than as integers).
Checking for NULL before calling the val_xxx()
methods only checks for such arguments that are
known to be NULLs at compile time.
The arguments that may or may not contain
NULLs (e.g. function calls and possibly others)
are not checked at all.
Fixed by first calling the val_xxx() method and
then checking for null in SEC_TO_TIME().
In addition QUARTER() was not returning 0 (as all the
val_int() functions do when processing a NULL value).
(4.1 version, with post-review fixes)
The fix for another Bug (6439) limited FROM_UNIXTIME() to
TIMESTAMP_MAX_VALUE which is 2145916799 or 2037-12-01 23:59:59 GMT,
however unix timestamp in general is not considered to be limited
by this value. All dates up to power(2,31)-1 are valid.
This patch extends allowed TIMESTAMP range so, that max
TIMESTAMP value is power(2,31)-1. It also corrects
FROM_UNIXTIME() and UNIX_TIMESTAMP() functions, so that
max allowed UNIX_TIMESTAMP() is power(2,31)-1. FROM_UNIXTIME()
is fixed accordingly to allow conversion of dates up to
2038-01-19 03:14:07 UTC. The patch also fixes CONVERT_TZ()
function to allow extended range of dates.
The main problem solved in the patch is possible overflows
of variables, used in broken-time representation to time_t
conversion (required for UNIX_TIMESTAMP).
From the manual:
date arithmetic operations require complete dates and do not work with
incomplete dates such as '2006-07-00' or badly malformed dates.
- bug #11655 "Wrong time is returning from nested selects - maximum time exists
- input and output TIME values were not validated properly in several conversion functions
- bug #20927 "sec_to_time treats big unsigned as signed"
- integer overflows were not checked in several functions. As a result, input values like 2^32 or 3600*2^32 were treated as 0
- BIGINT UNSIGNED values were treated as SIGNED in several functions
- in cases where both input string truncation and out-of-range TIME value occur, only 'truncated incorrect time value' warning was produced
- Type casting was not consequent, thus when adding a DATE type with
a WEEK interval the result type was DATETIME and not DATE as is the
norm.
- By changing the order of the date internal enumerations the deviant
type casting is resolved (Item_date_add_interval::fix_length_and_dec()
which determines result type for this operation assumes that addition
of any interval with value <= INTERVAL_DAY to date value will result
in date). There are two independant places to change:
interval_names[] and interval_type.
Corrected test case after removal of fix for bug#16377
type_date.test:
Corrected test case after removal of fix for bug#16377
item_cmpfunc.cc:
Removed changes to the agg_cmp_type() made in the for bug#16377
