MDEV-34033 Exchange partition with virtual columns fails

Extend Item::Eq_config with omit_table_names parameter to compare
without table names in Item_field::eq.

Tests are re-applied from commit 0cf2176.

Author: FooBarrior

mysql-test/main/partition_exchange.result

@@ -1250,6 +1250,28 @@ ALTER TABLE t1 EXCHANGE PARTITION p0 WITH TABLE t2;
 ERROR HY000: Tables have different definitions
 DROP TABLE t1, t2;
 #
+# MDEV-34033 Exchange partition with virtual columns fails
+#
+create or replace table t1(
+id int primary key,
+col1 int,
+col2 boolean as (col1 is null))
+partition by list (id) ( partition p1 values in (1)
+);
+create or replace table t1_working like t1;
+alter table t1_working remove partitioning;
+alter table t1 exchange partition p1 with table t1_working;
+create or replace table t2(
+id int primary key,
+col1 int,
+col2 boolean as (true))
+partition by list (id) ( partition p1 values in (1)
+);
+create or replace table t2_working like t2;
+alter table t2_working remove partitioning;
+alter table t2 exchange partition p1 with table t2_working;
+drop tables t1, t1_working, t2, t2_working;
+#
 # MDEV-35612 EXCHANGE PARTITION does not work for tables with unique blobs
 #
 create table t (a int, b text, unique (b), unique(a, b)) partition by list (a) (partition p0 values in (1,2), partition pdef default);

mysql-test/main/partition_exchange.test

@@ -552,6 +552,38 @@ ALTER TABLE t1 EXCHANGE PARTITION p0 WITH TABLE t2;
 # Cleanup
 DROP TABLE t1, t2;
 
+--echo #
+--echo # MDEV-34033 Exchange partition with virtual columns fails
+--echo #
+# this fails when the virtual persistent column
+# references another column
+create or replace table t1(
+  id int primary key,
+  col1 int,
+  col2 boolean as (col1 is null))
+  partition by list (id) ( partition p1 values in (1)
+);
+
+create or replace table t1_working like t1;
+alter table t1_working remove partitioning;
+alter table t1 exchange partition p1 with table t1_working;
+
+# this works when the virtual persistent column
+# does not reference another column
+create or replace table t2(
+  id int primary key,
+  col1 int,
+  col2 boolean as (true))
+  partition by list (id) ( partition p1 values in (1)
+);
+
+create or replace table t2_working like t2;
+alter table t2_working remove partitioning;
+alter table t2 exchange partition p1 with table t2_working;
+
+# Cleanup
+drop tables t1, t1_working, t2, t2_working;
+
 --echo #
 --echo # MDEV-35612 EXCHANGE PARTITION does not work for tables with unique blobs
 --echo #

sql/field.h

@@ -659,7 +659,7 @@ class Virtual_column_info: public Sql_alloc,
   bool cleanup_session_expr();
   bool fix_and_check_expr(THD *thd, TABLE *table);
   bool check_access(THD *thd);
-  inline bool is_equal(const Virtual_column_info* vcol) const;
+  inline bool is_equal(const Virtual_column_info* vcol, bool cmp_names) const;
   inline void print(String*);
 };
 

sql/item.cc

@@ -3557,7 +3557,7 @@ bool Item_field::eq(const Item *item, const Eq_config &config) const
     return 0;
 
   Item_field *item_field= (Item_field*) real_item2;
-  if (item_field->field && field)
+  if (!config.omit_table_names && item_field->field && field)
     return item_field->field == field;
   /*
     We may come here when we are trying to find a function in a GROUP BY
@@ -3571,12 +3571,13 @@ bool Item_field::eq(const Item *item, const Eq_config &config) const
   */
   return (!lex_string_cmp(system_charset_info, &item_field->name,
                           &field_name) &&
-	  (!item_field->table_name.str || !table_name.str ||
+          (config.omit_table_names ||
+           (!item_field->table_name.str || !table_name.str ||
 	   (!my_strcasecmp(table_alias_charset, item_field->table_name.str,
 			   table_name.str) &&
 	    (!item_field->db_name.str || !db_name.str ||
 	     (item_field->db_name.str && !strcmp(item_field->db_name.str,
-                                                 db_name.str))))));
+                                                 db_name.str)))))));
 }
 
 

sql/item.h

@@ -1274,7 +1274,9 @@ class Item :public Value_source,
   struct Eq_config
   {
     bool binary_cmp;        /**< Make binary comparison */
-    Eq_config(bool binary_cmp) : binary_cmp(binary_cmp) {}
+    bool omit_table_names;  /**< Skip table and db names comparison */
+    Eq_config(bool binary_cmp, bool omit_table_names= false)
+      : binary_cmp(binary_cmp), omit_table_names(omit_table_names) {}
   };
   virtual bool eq(const Item *, const Eq_config &config) const;
   enum_field_types field_type() const
@@ -8183,11 +8185,12 @@ bool fix_escape_item(THD *thd, Item *escape_item, String *tmp_str,
                      bool escape_used_in_parsing, CHARSET_INFO *cmp_cs,
                      int *escape);
 
-inline bool Virtual_column_info::is_equal(const Virtual_column_info* vcol) const
+inline bool Virtual_column_info::is_equal(const Virtual_column_info* vcol,
+                                          bool omit_table_names) const
 {
   return type_handler()  == vcol->type_handler()
       && stored_in_db == vcol->is_stored()
-      && expr->eq(vcol->expr, true);
+      && expr->eq(vcol->expr, {true, omit_table_names});
 }
 
 inline void Virtual_column_info::print(String* str)

sql/sql_table.cc

@@ -7048,7 +7048,7 @@ static bool fill_alter_inplace_info(THD *thd, TABLE *table,
             alter_expr= ALTER_STORED_GCOL_EXPR;
           else
             alter_expr= ALTER_VIRTUAL_GCOL_EXPR;
-          if (!field->vcol_info->is_equal(new_field->vcol_info))
+          if (!field->vcol_info->is_equal(new_field->vcol_info, false))
           {
             ha_alter_info->handler_flags|= alter_expr;
             value_changes= true;
@@ -7522,7 +7522,7 @@ bool mysql_compare_tables(TABLE *table, Alter_info *alter_info,
     {
       if (!tmp_new_field->field->vcol_info)
         DBUG_RETURN(false);
-      if (!field->vcol_info->is_equal(tmp_new_field->field->vcol_info))
+      if (!field->vcol_info->is_equal(tmp_new_field->field->vcol_info, true))
         DBUG_RETURN(false);
     }