The Year 1925 is a starting point because most of the timezones
switched to saner (mostly 15-minutes based) offsets somewhere
during 1924 or before. And that significantly simplifies implementation.
2238 is to simplify arithmetics for sanitizing LUT index access;
there are less than 0x1ffff days from 1925.
* Extended DateLUTImpl internal LUT to 0x1ffff items, some of which
represent negative (pre-1970) time values.
As a collateral benefit, Date now correctly supports dates up to 2149
(instead of 2106).
* Added a new strong typedef ExtendedDayNum, which represents dates
pre-1970 and post 2149.
* Functions that used to return DayNum now return ExtendedDayNum.
* Refactored DateLUTImpl to untie DayNum from the dual role of being
a value and an index (due to negative time). Index is now a different
type LUTIndex with explicit conversion functions from DatNum, time_t,
and ExtendedDayNum.
* Updated DateLUTImpl to properly support values close to epoch start
(1970-01-01 00:00), including negative ones.
* Reduced resolution of DateLUTImpl::Values::time_at_offset_change
to multiple of 15-minutes to allow storing 64-bits of time_t in
DateLUTImpl::Value while keeping same size.
* Minor performance updates to DateLUTImpl when building month LUT
by skipping non-start-of-month days.
* Fixed extractTimeZoneFromFunctionArguments to work correctly
with DateTime64.
* New unit-tests and stateless integration tests for both DateTime
and DateTime64.
There was no specializations for toDateTime64(<numeric>), and because of
this default decimal conversion was used, however this is not enough for
DateTime/DateTime64 types, since the date may overflow and the proper
check is required (like DateTime has), and this what UBsan found [1]:
../src/IO/WriteHelpers.h:812:33: runtime error: index 508 out of bounds for type 'const char [201]' Received signal -3 Received signal Unknown signal (-3)
Backtrace:
(gdb) bt
0 LocalDateTime::LocalDateTime (this=0x7fffffff8418, year_=1970, month_=1 '\001', day_=1 '\001', hour_=2 '\002', minute_=0 '\000', second_=254 '\376') at LocalDateTime.h:83
1 0x00000000138a5edb in DB::writeDateTimeText<(char)45, (char)58, (char)32, (char)46> (datetime64=..., scale=7, buf=..., date_lut=...) at WriteHelpers.h:852
2 0x0000000019c379b4 in DB::DataTypeDateTime64::serializeText (this=0x7ffff5c4b0d8, column=..., row_num=0, ostr=..., settings=...) at DataTypeDateTime64.cpp:66
3 0x0000000019d297e4 in DB::IDataType::serializeAsText (this=0x7ffff5c4b0d8, column=..., row_num=0, ostr=..., settings=...) at IDataType.cpp:387
[1]: https://clickhouse-test-reports.s3.yandex.net/19527/cea8ae162ffbf92e5ed29304ab010704c5d611c8/fuzzer_ubsan/report.html#fail1
Also fix CAST for DateTime64
