MDEV-6312 HA_MUST_USE_TABLE_CONDITION_PUSHDOWN is not accounted by init_read_record()

sql/records.cc

@@ -287,9 +287,7 @@ bool init_read_record(READ_RECORD *info,THD *thd, TABLE *table,
 				  thd->variables.read_buff_size);
   }
   /* Condition pushdown to storage engine */
-  if ((thd->variables.optimizer_switch &
-       OPTIMIZER_SWITCH_ENGINE_CONDITION_PUSHDOWN) && 
-      select && select->cond && 
+  if (thd->use_cond_push(table->file) && select && select->cond && 
       (select->cond->used_tables() & table->map) &&
       !table->file->pushed_cond)
     table->file->cond_push(select->cond);

sql/sql_class.h

@@ -2894,6 +2894,11 @@ class THD :public Statement,
 
   // End implementation of MDL_context_owner interface.
 
+  inline bool use_cond_push(handler *file)
+  {
+    return (variables.optimizer_switch & OPTIMIZER_SWITCH_ENGINE_CONDITION_PUSHDOWN)
+        || (file->ha_table_flags() & HA_MUST_USE_TABLE_CONDITION_PUSHDOWN);
+  }
   inline bool is_strict_mode() const
   {
     return (bool) (variables.sql_mode & (MODE_STRICT_TRANS_TABLES |

sql/sql_select.cc

@@ -9530,11 +9530,7 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
           if (tab->table)
           {
             tab->table->file->pushed_cond= NULL;
-            if (((thd->variables.optimizer_switch &
-                               OPTIMIZER_SWITCH_ENGINE_CONDITION_PUSHDOWN) ||
-                 (tab->table->file->ha_table_flags() &
-                  HA_MUST_USE_TABLE_CONDITION_PUSHDOWN)) &&
-                !first_inner_tab)
+            if (thd->use_cond_push(tab->table->file) && !first_inner_tab)
             {
               COND *push_cond= 
               make_cond_for_table(thd, tmp, current_map, current_map,
@@ -23559,11 +23555,7 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table,
           {
             const COND *pushed_cond= tab->table->file->pushed_cond;
 
-            if (((thd->variables.optimizer_switch &
-                 OPTIMIZER_SWITCH_ENGINE_CONDITION_PUSHDOWN) ||
-                 (tab->table->file->ha_table_flags() &
-                  HA_MUST_USE_TABLE_CONDITION_PUSHDOWN)) &&
-                pushed_cond)
+            if (thd->use_cond_push(tab->table->file) && pushed_cond)
             {
               eta->push_extra(ET_USING_WHERE_WITH_PUSHED_CONDITION);
               /*