The fix was in the call the open_normal_and_derived_tables() from
the function mysql_test_select() and it was similar to those from
the patch for mdev-13107.
Added explicit PREPARE statements that failed in --ps-protocol.
The problems were in the code of sql_show.cc. There the tables
could be opened in such a way that mysql_derived_init() never
worked for CTE tables. As a result they were not marked as
derived and mysql_handle_derived() were not called for derived
tables used in their specifications.
In the current code temporary tables we identified and opened before
other tables. CTE tables are identified in the same procedure as
regular tables. When a temporary table and a CTE table have the same
name T any reference to T that is in the scope of the CTE declaration
must be associated with this CTE. Yet it was not done properly.
When a reference to T was found in the scope of the declaration
of CTE T a pointer to this CTE was set in the reference. No check
that the reference had been already associated with a temporary table
was done. As a result, if the temporary table T had been created then
the reference to T was considered simultaneously as reference to the CTE
named T and as a reference to the temporary table named T. This
confused the code that were executed later and caused a crash of
the server.
Now when a table reference is associated with a CTE any previous
association with a temporary table is dropped.
This problem could be easily avoided if the temporary tables were
not identified prematurely.
as reference to CTE named T and
When a CTE referring to another CTE from the same with clause
was used twice then the server could not find the second CTE and
reported a bogus error message.
This happened because for any unit that was created as a clone of
a CTE specification the pointer to the WITH clause that owned this CTE
was not set.
The bug was caused by a wrong order of statements in With_clause::print().
As a result any view definition containing WITH clause with several
CTE specifications was put the frm file in a syntactically incorrect
form.
When a query containing a WITH clause is printed by EXPLAIN
EXTENDED command there should not be any data expansion in
the query specifications of the WITH elements of this WITH
clause.
The code for st_select_lex::find_table_def_in_with_clauses()
did not take into account the fact that the specs for mergeable
CTEs were cloned and were not processed by the function
With_element::check_dependencies_in_spec().
Make the new (CTE-related) code in set_explain_type to take into
account that some JOIN_TABs are non-merged semi-joins, and do not
have a TABLE object.
Added comments.
Added reaction for exceeding maximum number of elements in with clause.
Added a test case to check this reaction.
Added a test case where the specification of a recursive table
uses two non-recursive with tables.
explain for the query containing WITH clause
with an unreferenced CTE caused a crash.
Added a test covered this case.
Also added a test for usage CTE in different parts of union.
The patch for bug mdev-9937 actually did not fix the problem
of name resolution for tables used in views referred in queries
with WITH clauses. This fix corrects the patch.
Added test cases to check the fix.
Fixed the problem of wrong types of recursive tables when the type of anchor part does not coincide with the
type of recursive part.
Prevented usage of marerialization and subquery cache for subqueries with recursive references.
Introduced system variables 'max_recursion_level'.
Added a test case to test usage of this variable.
When the specification of a WITH table referred to a view
that used a based table with the same name as the WITH table
the server went into an infinite loop because it erroneously
resolved the reference to the base table as the reference to
the WITH table.
With tables used in a view cannot be searched for beyond the
scope the view.
of mdev-8789.
Fixed a bug in TABLE_LIST::print.
Fixed another bug for the case when the definition of a
WITH table contained column list while the join in the main
query used two instances of this table.
