Fixed bug mdev-11138.

Supported usage of expressions with window functions in SELECTs without tables.

Author: igorbabaev

mysql-test/r/win.result

@@ -2521,3 +2521,27 @@ id	rnk
 2	2
 drop view v1;
 drop table t1;
+#
+# MDEV-11138: window function in the query without tables 
+#
+select row_number() over ();
+row_number() over ()
+1
+select count(*) over ();
+count(*) over ()
+1
+select sum(5) over ();
+sum(5) over ()
+5
+select row_number() over (), sum(5) over ();
+row_number() over ()	sum(5) over ()
+1	5
+select row_number() over (order by 2);
+row_number() over (order by 2)
+1
+select row_number() over (partition by 2);
+row_number() over (partition by 2)
+1
+select row_number() over (partition by 4 order by 1+2);
+row_number() over (partition by 4 order by 1+2)
+1

mysql-test/t/win.test

@@ -1535,3 +1535,15 @@ select * from v1;
 
 drop view v1;
 drop table t1;
+
+--echo #
+--echo # MDEV-11138: window function in the query without tables 
+--echo #
+
+select row_number() over ();
+select count(*) over ();
+select sum(5) over ();
+select row_number() over (), sum(5) over ();
+select row_number() over (order by 2);
+select row_number() over (partition by 2);
+select row_number() over (partition by 4 order by 1+2);

sql/sql_select.cc

@@ -1439,6 +1439,13 @@ JOIN::optimize_inner()
  {
  DBUG_PRINT("info",("No tables"));
  error= 0;
+ if (select_lex->have_window_funcs())
+ {
+ if (!join_tab && 
+ !(join_tab= (JOIN_TAB*) thd->alloc(sizeof(JOIN_TAB))))
+ DBUG_RETURN(1);
+ need_tmp= 1;
+ }
  if (make_aggr_tables_info())
  DBUG_RETURN(1);
  goto setup_subq_exit;
@@ -2186,7 +2193,7 @@ bool JOIN::make_aggr_tables_info()
  Setup last table to provide fields and all_fields lists to the next
  node in the plan.
  */
- if (join_tab)
+ if (join_tab && top_join_tab_count)
  {
  join_tab[top_join_tab_count - 1].fields= &fields_list;
  join_tab[top_join_tab_count - 1].all_fields= &all_fields;
@@ -2310,7 +2317,8 @@ bool JOIN::make_aggr_tables_info()
  single table queries, thus it is sufficient to test only the first
  join_tab element of the plan for its access method.
  */
- if (join_tab && join_tab->is_using_loose_index_scan())
+ if (join_tab && top_join_tab_count &&
+ join_tab->is_using_loose_index_scan())
  tmp_table_param.precomputed_group_by=
  !join_tab->is_using_agg_loose_index_scan();
 
@@ -2770,7 +2778,7 @@ JOIN::create_postjoin_aggr_table(JOIN_TAB *tab, List<Item> *table_fields,
  tmp_table_param.using_outer_summary_function=
  tab->tmp_table_param->using_outer_summary_function;
  tab->join= this;
- DBUG_ASSERT(tab > tab->join->join_tab);
+ DBUG_ASSERT(tab > tab->join->join_tab || !top_join_tab_count);
  (tab - 1)->next_select= sub_select_postjoin_aggr;
  tab->aggr= new (thd->mem_root) AGGR_OP(tab);
  if (!tab->aggr)
@@ -3424,7 +3432,6 @@ JOIN::destroy()
 
  if (join_tab)
  {
- DBUG_ASSERT(table_count+aggr_tables > 0);
  for (JOIN_TAB *tab= first_linear_tab(this, WITH_BUSH_ROOTS,
  WITH_CONST_TABLES);
  tab; tab= next_linear_tab(this, tab, WITH_BUSH_ROOTS))

sql/sql_window.cc

@@ -2801,6 +2801,11 @@ bool Window_funcs_sort::setup(THD *thd, SQL_SELECT *sel,
  sort_order= order;
  }
  filesort= new (thd->mem_root) Filesort(sort_order, HA_POS_ERROR, true, NULL);
+ if (!join_tab->join->top_join_tab_count)
+ {
+ filesort->tracker=
+ new (thd->mem_root) Filesort_tracker(thd->lex->analyze_stmt);
+ }
 
  /* Apply the same condition that the subsequent sort has. */
  filesort->select= sel;