argument can lead to a wrong result.
md5() and sha() functions treat their arguments as case sensitive strings.
But when they are compared their arguments were compared as a case
insensitive strings which leads to two functions with different arguments
and thus different results to being identical. This can lead to a wrong
decision made in the range optimizer and thus lead to a wrong result set.
Item_func_md5::fix_length_and_dec() and Item_func_sha::fix_length_and_dec()
functions now set binary collation on their arguments.
BUG #11104
Took out the offset-=delimiter_length-1 out of the for loop. It was causing
basically this:
select substring_index('the king of the the hill', 'the', -2) to not work.
The first iteration, offset would be initialised to 24, then strstr would
point at 'the king of the the* hill' ('*'means right before the
character following), returning a offset of 16. The for loop would then
decrement offset by two (3 - 1), to 14, now pointing at
"the king of th*e the hill", _skipping_ past the 'e' in the second to last
'the', and therefore strstr would never have a chance of matching the
second to last 'the', then moving on to the 'the' at the begginning of the
string!
In a nutshell, offset was being decremented by too great a value, preventing
the second to last 'the' from being ever found, hence the result of
'king of the the hill' from the query that is reported in the bug report
func_str.test:
BUG #11104
Added tests to make sure fix addresses issues in original bug report
func_str.result:
BUG #11104
New results for new tests
Added a test case for bug #10124.
sql_select.h, item_subselect.cc, sql_select.cc:
Fixed bug #10124.
The copy method of the store_key classes can return
STORE_KEY_OK=0, STORE_KEY_FATAL=1, STORE_KEY_CONV=2 now.
field.cc:
Fixed bug #10124.
When ussuing a warning the store methods return 2 instead of 1 now.
fixing test results accordingly.
func_system.test:
New test that illegal mix of collations does not happen anymore.
item_strfunc.h:
safe_charset_converter() was added for system constants.
item_strfunc.cc:
safe_charset_converter() was added for system constants.
item_func.cc, item.h, item.cc:
Bug#8291: Illegal collation mix with USER() function.
After discussion with PeterG and Serge, a new coercibility
level for "system constants" was introduced, between
COERRIBLE and IMPLICIT. Thus:
SELECT col1 = USER() FROM t1; - is done according to col1 collation.
SELECT 'string' = USER(); - is done according to USER() collation.
At the same time, "nagg" and "strong" members were removed as unused.
item_create.cc:
Version is a system constant too.
