MDEV-10850 Wrong result for WHERE .. (f2=TO_BASE64('test') OR f2=TO_BASE64('TEST'))
Problem N1: MDEV-10425
Item_func_{md5|sha|sha2}::fix_length_and_dec() changed args[0]->collation
to force binary comparison in args[0]->eq().
It was done to treat e.g. MD5('a') and MD5('A') as different values.
It is wrong for a Item_func_xxx to modify its arguments.
Item_func_conv_charset did not expect that and crashed on assert.
Problem N2: MDEV-10850
Item_func_to_base64, Item_func_password, Item_func_hex are also case sensitive
hash functions, but they did not compare their arguments as binary.
Solution:
- Removing the code changing args[0]->collation
- Introducing Item_str_ascii_checksum_func as a common parent
for Item_func_{md5|sha|sha2|password|hex|to_base64}
and overriding its eq() method to compare arguments binary.
~40% bugfixed(*) applied
~40$ bugfixed reverted (incorrect or we're not buggy)
~20% bugfixed applied, despite us being not buggy
(*) only changes in the server code, e.g. not cmakefiles
Item_func_make_set wasn't taking into account the first argument when
calculating maybe_null.
sql/item_strfunc.cc:
rewrite Item_func_make_set, removing separate storage of the first argument
sql/item_strfunc.h:
rewrite Item_func_make_set, removing separate storage of the first argument
Bug#12985021 SIMPLE QUERY WITH DECIMAL NUMBERS TAKE AN
When parsing the fractional part of a string which
is to be converted to double, we can stop after a few digits:
the extra digits will not contribute to the actual result anyways.
mysql-test/r/func_str.result:
New tests.
mysql-test/t/func_str.test:
New tests.
strings/dtoa.c:
The problem was s2b() multiplying and adding hundreds-of-thousands
of ever smaller fractions.
mysql-test/r/func_str.result:
New test cases.
mysql-test/t/func_str.test:
New test cases.
strings/dtoa.c:
Increasing the buffer size slightly made some queries pass without leaks.
Adding Bfree(p51, alloc) fixed the remaining leaks.
Failure to check the return state of a longlong2str() call
caused a crash. This could happen if a user executed the sql
function CONV() with certain parameters.
The patch fixes the issue by checking that the returned pointer
isn't NULL.
other crashes
Some string manipulating SQL functions use a shared string object intended to
contain an immutable empty string. This object was used by the SQL function
SUBSTRING_INDEX() to return an empty string when one argument was of the wrong
datatype. If the string object was then modified by the sql function INSERT(),
undefined behavior ensued.
Fixed by instead modifying the string object representing the function's
result value whenever string manipulating SQL functions return an empty
string.
Relevant code has also been documented.
