An integer overflow in number->string conversion caused completely
wrong output of the number LONGLONG_MIN with gcc 4.2.1.
Fixed by eliminating the overflow, using only operations that are
well-defined in ANSI C.
JOIN, and ORDER BY
Problem: improper maximum length calculation of the CASE function leads to
decimal value truncation (storing/retrieving decimal field values).
Fix: accurately calculate maximum length/unsigned flag/decimals parameters
of the CASE function.
file .\ha_innodb.
Problem: if a partial unique key followed by a non-partial one we declare
the second one as a primary key.
Fix: sort non-partial unique keys before partial ones.
some platforms
Since the behavior of write(fd, buf, 0) is undefined, it may fail with
EFAULT on some architectures when buf == NULL. The error was propagated
up to a caller, since my_write() code did not handle it properly.
Fixed by checking the 'number of bytes' argument in my_write() and
returning before calling the write() system call when there is nothing
to write.
Problem: lying to the optimizer that a function (Item_func_inet_ntoa)
cannot return NULL values leads to unexpected results (in the case group
keys creation/comparison is broken).
Fix: Item_func_inet_ntoa::maybe_null should be set properly.
Previously, UDF *_init functions were passed constant strings with erroneous lengths. The length came from the containing variable's size, not the length of the value itself.
Now the *_init functions get the constant as a null terminated string with the correct length supplied too.
CPUs / Intel's ICC compile
The bug is a combination of two problems:
1. IA64/ICC MySQL binaries use glibc's qsort(), not the one in mysys.
2. The order relation implemented by join_tab_cmp() is not transitive,
i.e. it is possible to choose such a, b and c that (a < b) && (b < c)
but (c < a). This implies that result of a sort using the relation
implemented by join_tab_cmp() depends on the order in which
elements are compared, i.e. the result is implementation-specific. Since
choose_plan() uses qsort() to pre-sort the
join tables using join_tab_cmp() as a compare function, the results of
the sorting may vary depending on qsort() implementation.
It is neither possible nor important to implement a better ordering
algorithm in join_tab_cmp(). Therefore the only way to fix it is to
force our own qsort() to be used by renaming it to my_qsort(), so we don't depend
on linker to decide that.
This patch also "fixes" bug #20530: qsort redefinition violates the
standard.
The root cause of the issue was that the CREATE FUNCTION grammar,
for User Defined Functions, was using the sp_name rule.
The sp_name rule is intended for fully qualified stored procedure names,
like either ident.ident, or just ident but with a default database
implicitly selected.
A UDF does not have a fully qualified name, only a name (ident), and should
not use the sp_name grammar fragment during parsing.
The fix is to re-organize the CREATE FUNCTION grammar, to better separate:
- creating UDF (no definer, can have AGGREGATE, simple ident)
- creating Stored Functions (definer, no AGGREGATE, fully qualified name)
With the test case provided, another issue was exposed which is also fixed:
the DROP FUNCTION statement was using sp_name and also failing when no database
is implicitly selected, when droping UDF functions.
The fix is also to change the grammar so that DROP FUNCTION works with
both the ident.ident syntax (to drop a stored function), or just the ident
syntax (to drop either a UDF or a Stored Function, in the current database)
