MDEV-6400: "ANALYZE SELECT ... INTO @var" doesn't set @var

Make ANALYZE work for
- ANALYZE SELECT ... INTO @var
- ANALYZE INSERT SELECT ...;
- ANALYZE SELECT .. INTO OUTFILE

mysql-test/r/analyze_stmt.result

@@ -276,3 +276,20 @@ select * from t1;
 a	b
 1	2
 drop table t1;
+#
+# MDEV-6400 "ANALYZE SELECT ... INTO @var" doesn't set @var
+#
+create table t1(a int);
+insert into t1 values (1),(2);
+analyze select a from t1 where a <2 into @var;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	2	100.00	50.00	Using where
+analyze select a from t1 into @var;
+ERROR 42000: Result consisted of more than one row
+analyze insert into t1 select * from t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	2	100.00	100.00	Using temporary
+analyze select * into outfile '../../tmp/data1.tmp' from t1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	4	4	100.00	100.00	
+drop table t1;

mysql-test/t/analyze_stmt.test

@@ -217,3 +217,19 @@ analyze replace t1 values (1,2);
 select * from t1;
 drop table t1;
 
+--echo #
+--echo # MDEV-6400 "ANALYZE SELECT ... INTO @var" doesn't set @var
+--echo #
+create table t1(a int);
+insert into t1 values (1),(2);
+
+analyze select a from t1 where a <2 into @var;
+--error ER_TOO_MANY_ROWS
+analyze select a from t1 into @var;
+
+analyze insert into t1 select * from t1;
+
+analyze select * into outfile '../../tmp/data1.tmp' from t1;
+--remove_file $MYSQLTEST_VARDIR/tmp/data1.tmp
+
+drop table t1;

sql/sql_class.cc

@@ -2710,7 +2710,7 @@ bool select_to_file::send_eof()
   if (mysql_file_close(file, MYF(MY_WME)) || thd->is_error())
     error= true;
 
-  if (!error)
+  if (!error && !suppress_my_ok)
   {
     ::my_ok(thd,row_count);
   }
@@ -3786,11 +3786,14 @@ bool select_dumpvar::send_eof()
   if (thd->is_error())
     return true;
 
-  ::my_ok(thd,row_count);
+  if (!suppress_my_ok)
+    ::my_ok(thd,row_count);
+
   return 0;
 }
 
 
+
 bool
 select_materialize_with_stats::
 create_result_table(THD *thd_arg, List<Item> *column_types,

sql/sql_class.h

@@ -3956,6 +3956,14 @@ public:
   {
     unit->offset_limit_cnt= 0;
   }
+
+  /*
+    This returns
+    - FALSE if the class sends output row to the client
+    - TRUE if the output is set elsewhere (a file, @variable, or table).
+    Currently all intercepting classes derive from select_result_interceptor.
+  */
+  virtual bool is_result_interceptor()=0;
 };
 
 
@@ -3986,6 +3994,8 @@ public:
 
 /*
   This is a select_result_sink which stores the data in text form.
+
+  It is only used to save EXPLAIN output.
 */
 
 class select_result_text_buffer : public select_result_sink
@@ -4014,7 +4024,7 @@ private:
 class select_result_interceptor: public select_result
 {
 public:
-  select_result_interceptor()
+  select_result_interceptor() : suppress_my_ok(false)
   {
     DBUG_ENTER("select_result_interceptor::select_result_interceptor");
     DBUG_PRINT("enter", ("this 0x%lx", (ulong) this));
@@ -4022,6 +4032,15 @@ public:
   }              /* Remove gcc warning */
   uint field_count(List<Item> &fields) const { return 0; }
   bool send_result_set_metadata(List<Item> &fields, uint flag) { return FALSE; }
+  bool is_result_interceptor() { return true; }
+
+  /*
+    Instruct the object to not call my_ok(). Client output will be handled
+    elsewhere. (this is used by ANALYZE $stmt feature).
+  */
+  void disable_my_ok_calls() { suppress_my_ok= true; }
+protected:
+  bool suppress_my_ok;
 };
 
 
@@ -4040,6 +4059,7 @@ public:
   virtual bool check_simple_select() const { return FALSE; }
   void abort_result_set();
   virtual void cleanup();
+  bool is_result_interceptor() { return true; }
 };
 
 

sql/sql_insert.cc

@@ -3712,6 +3712,10 @@ bool select_insert::send_eof()
     table->file->print_error(error,MYF(0));
     DBUG_RETURN(1);
   }
+
+  if (suppress_my_ok)
+    DBUG_RETURN(0);
+
   char buff[160];
   if (info.ignore)
     sprintf(buff, ER(ER_INSERT_INFO), (ulong) info.records,

sql/sql_parse.cc

@@ -3814,6 +3814,9 @@ end_with_restore_list:
                                                  lex->duplicates,
                                                  lex->ignore)))
       {
+        if (lex->analyze_stmt)
+          ((select_result_interceptor*)sel_result)->disable_my_ok_calls();
+
 	res= handle_select(thd, lex, sel_result, OPTION_SETUP_TABLES_DONE);
         /*
           Invalidate the table in the query cache if something changed
@@ -3833,7 +3836,7 @@ end_with_restore_list:
         delete sel_result;
       }
 
-      if (!res && explain)
+      if (!res && (explain || lex->analyze_stmt))
         res= thd->lex->explain->send_explain(thd);
 
       /* revert changes for SP */
@@ -5649,12 +5652,18 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables)
     }
     else
     {
-      Protocol *save_protocol;
+      Protocol *save_protocol= NULL;
       if (lex->analyze_stmt)
       {
-        result= new select_send_analyze();
-        save_protocol= thd->protocol;
-        thd->protocol= new Protocol_discard(thd);
+        if (result && result->is_result_interceptor())
+          ((select_result_interceptor*)result)->disable_my_ok_calls();
+        else 
+        {
+          DBUG_ASSERT(thd->protocol);
+          result= new select_send_analyze();
+          save_protocol= thd->protocol;
+          thd->protocol= new Protocol_discard(thd);
+        }
       }
       else
       {
@@ -5668,8 +5677,11 @@ static bool execute_sqlcom_select(THD *thd, TABLE_LIST *all_tables)
 
       if (lex->analyze_stmt)
       {
-        delete thd->protocol;
-        thd->protocol= save_protocol;
+        if (save_protocol)
+        {
+          delete thd->protocol;
+          thd->protocol= save_protocol;
+        }
         if (!res)
           res= thd->lex->explain->send_explain(thd);
       }