Merge remote-tracking branch 'origin/10.2' into bb-10.2-ext

1 files changed, 71 insertions, 1 deletions

diff --git a/sql/sql_cte.cc b/sql/sql_cte.cc
index 7c2a8cf9e65..c163044547f 100644
--- a/sql/sql_cte.cc
+++ b/sql/sql_cte.cc
@@ -141,7 +141,7 @@ bool With_clause::check_dependencies()
 
   /*
     Mark those elements where tables are defined with direct or indirect
-   make recursion.
+    recursion.
   */ 
   for (With_element *with_elem= with_list.first;
        with_elem;
@@ -342,6 +342,8 @@ void With_element::check_dependencies_in_select(st_select_lex *sl,
       tbl->with_internal_reference_map= get_elem_map();
       if (in_subq)
         sq_dep_map|= tbl->with->get_elem_map();
+      else
+        top_level_dep_map|= tbl->with->get_elem_map();
     }
   }
   /* Now look for the dependencies in the subqueries of sl */
@@ -353,6 +355,53 @@ void With_element::check_dependencies_in_select(st_select_lex *sl,
 
 /**
   @brief
+    Find a recursive reference to this with element in subqueries of a select
+ 
+  @param  sel      The select in whose subqueries the reference
+                   to be looked for
+
+  @details
+    The function looks for a recursive reference to this with element in
+    subqueries of select sl. When the first such reference is found
+    it is returned as the result.
+    The function assumes that the identification of all CTE references
+    has been performed earlier.
+
+  @retval
+    Pointer to the found recursive reference if the search succeeded
+    NULL - otherwise 
+*/
+
+TABLE_LIST *With_element::find_first_sq_rec_ref_in_select(st_select_lex *sel)
+{
+  TABLE_LIST *rec_ref= NULL;
+  st_select_lex_unit *inner_unit= sel->first_inner_unit();
+  for (; inner_unit; inner_unit= inner_unit->next_unit())
+  {
+    st_select_lex *sl= inner_unit->first_select();
+    for (; sl; sl= sl->next_select())
+    {
+      for (TABLE_LIST *tbl= sl->table_list.first; tbl; tbl= tbl->next_local)
+      {
+        if (tbl->derived || tbl->nested_join)
+          continue;
+        if (tbl->with && tbl->with->owner== this->owner &&
+            (tbl->with_internal_reference_map & mutually_recursive))
+	{
+	  rec_ref= tbl;
+          return rec_ref;
+        }
+      }
+      if ((rec_ref= find_first_sq_rec_ref_in_select(sl)))
+        return rec_ref;
+    } 
+  }
+  return 0;
+}
+
+
+/**
+  @brief
     Find the dependencies of this element on its siblings in a unit
  
   @param  unit     The unit where to look for the dependencies
@@ -602,6 +651,10 @@ void With_clause::move_anchors_ahead()
   @details
     If the specification of this with element contains anchors the method
     moves them at the very beginning of the specification.
+    Additionally for the other selects of the specification if none of them
+    contains a recursive reference to this with element or a mutually recursive
+    one the method looks for the first such reference in the first recursive 
+    select and set a pointer to it in this->sq_rec_ref.   
 */
 
 void With_element::move_anchors_ahead()
@@ -618,6 +671,11 @@ void With_element::move_anchors_ahead()
       sl->move_node(new_pos);
       new_pos= sl->next_select();
     }
+    else if (!sq_rec_ref && no_rec_ref_on_top_level())
+    {
+      sq_rec_ref= find_first_sq_rec_ref_in_select(sl);
+      DBUG_ASSERT(sq_rec_ref != NULL);
+    }
     last_sl= sl;
   }
   if (spec->union_distinct)
@@ -967,6 +1025,17 @@ With_element *st_select_lex::find_table_def_in_with_clauses(TABLE_LIST *table)
 
 bool TABLE_LIST::set_as_with_table(THD *thd, With_element *with_elem)
 {
+  if (table)
+  {
+    /*
+      This table was prematurely identified as a temporary table.
+      We correct it here, but it's not a nice solution in the case
+      when the temporary table with this name is not used anywhere
+      else in the query.
+    */
+    thd->mark_tmp_table_as_free_for_reuse(table);
+    table= 0;
+  }
   with= with_elem;
   if (!with_elem->is_referenced() || with_elem->is_recursive)
     derived= with_elem->spec;
@@ -1228,6 +1297,7 @@ bool st_select_lex::check_subqueries_with_recursive_references()
 	continue;
       Item_subselect *subq= (Item_subselect *) sl_master->item;
       subq->with_recursive_reference= true;
+      subq->register_as_with_rec_ref(tbl->with);
     }
   }
   return false;