Before this fix, a call to a User Defined Function (UDF) could,
under some circumstances, be interpreted as a call to a Stored function
instead. This occurred if a native function was invoked in the parameters
for the UDF, as in "select my_udf(abs(x))".
The root cause of this defect is the introduction, by the fix for Bug 21809,
of st_select_lex::udf_list, and it's usage in the parser in sql_yacc.yy
in the rule function_call_generic (in 5.1).
While the fix itself for Bug 21809 is correct in 5.0, the code change
merged into the 5.1 release created the issue, because the calls in 5.1 to :
- lex->current_select->udf_list.push_front(udf)
- lex->current_select->udf_list.pop()
are not balanced in case of native functions, causing the udf_list,
which is really a stack, to be out of sync with the internal stack
maintained by the bison parser.
Instead of moving the call to udf_list.pop(), which would have fixed the
symptom, this patch goes further and removes the need for udf_list.
This is motivated by two reasons:
a) Maintaining a stack in the MySQL code in sync with the stack maintained
internally in sql_yacc.cc (not .yy) is extremely dependent of the
implementation of yacc/bison, and extremely difficult to maintain.
It's also totally dependent of the structure of the grammar, and has a risk
to break with regression defects each time the grammar itself is changed.
b) The previous code did report construct like "foo(expr AS name)" as
syntax errors (ER_PARSER_ERROR), which is incorrect, and misleading.
The syntax is perfectly valid, as this expression is valid when "foo" is
a UDF. Whether this syntax is legal or not depends of the semantic of "foo".
With this change:
a) There is only one stack (in bison), and no List<udf_func> to maintain.
b) "foo(expr AS name)", when used incorrectly, is reported as semantic error:
- ER_WRONG_PARAMETERS_TO_NATIVE_FCT (for native functions)
- ER_WRONG_PARAMETERS_TO_STORED_FCT (for stored functions)
This is achieved by the changes implemented in item_create.cc
Backport of functionality in private 5.2 tree.
Added new language to parser, new mysql.servers table and associated code
to be used by the federated storage engine to allow central connection information
per WL entry.
Bug#21025 (misleading error message when creating functions named 'x', or 'y')
Bug#22619 (Spaces considered harmful)
This change contains a fix to report warnings or errors, and multiple tests
cases.
Before this fix, name collisions between:
- Native functions
- User Defined Functions
- Stored Functions
were not systematically reported, leading to confusing behavior.
I) Native / User Defined Function
Before this fix, is was possible to create a UDF named "foo", with the same
name as a native function "foo", but it was impossible to invoke the UDF,
since the syntax "foo()" always refer to the native function.
After this fix, creating a UDF fails with an error if there is a name
collision with a native function.
II) Native / Stored Function
Before this fix, is was possible to create a SF named "db.foo", with the same
name as a native function "foo", but this was confusing since the syntax
"foo()" would refer to the native function. To refer to the Stored Function,
the user had to use the "db.foo()" syntax.
After this fix, creating a Stored Function reports a warning if there is a
name collision with a native function.
III) User Defined Function / Stored Function
Before this fix, creating a User Defined Function "foo" and a Stored Function
"db.foo" are mutually exclusive operations. Whenever the second function is
created, an error is reported. However, the test suite did not cover this
behavior.
After this fix, the behavior is unchanged, and is now covered by test cases.
Note that the code change in this patch depends on the fix for Bug 21114.
Due to the complexity of this change, everything is documented in WL#3565
This patch is the third iteration, it takes into account the comments
received to date.
Bug #21785 "Server crashes after rename of the log table" and
Bug #21966 "Strange warnings on create like/repair of the log
tables"
According to the patch, from now on, one should use RENAME to
perform a log table rotation (this should also be reflected in
the manual).
Here is a sample:
use mysql;
CREATE TABLE IF NOT EXISTS general_log2 LIKE general_log;
RENAME TABLE general_log TO general_log_backup, general_log2 TO general_log;
The rules for Rename of the log tables are following:
IF 1. Log tables are enabled
AND 2. Rename operates on the log table and nothing is being
renamed to the log table.
DO 3. Throw an error message.
ELSE 4. Perform rename.
The very RENAME query will go the the old (backup) table. This is
consistent with the behavoiur we have with binlog ROTATE LOGS
statement.
Other problems, which are solved by the patch are:
1) Now REPAIR of the log table is exclusive operation (as it should be), this
also eliminates lock-related warnings. and
2) CREATE LIKE TABLE now usese usual read lock on the source table rather
then name lock, which is too restrictive. This way we get rid of another
log table-related warning, which occured because of the above fact
(as a side-effect, name lock resulted in a warning).
On an INSERT into an updatable but non-insertable view an error message was
issued stating the view being not updatable. This can lead to a confusion of a
user.
A new error message is introduced. Is is showed when a user tries to insert
into a non-insertable view.
