vcols: cannot use CONTEXT_ANALYSIS_ONLY_VCOL_EXPR on fix_fields

because CONTEXT_ANALYSIS_ONLY_VCOL_EXPR can be used only for,
exactly, context analysys. Items fixed that way cannot be evaluated.
But vcols are going to be evaluated, so they have to be fixed properly,
for evaluation.

mysql-test/suite/vcol/r/vcol_misc.result

@@ -227,7 +227,7 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` bigint(20) DEFAULT NULL,
-  `b` bigint(20) GENERATED ALWAYS AS (`a` > '2') VIRTUAL
+  `b` bigint(20) GENERATED ALWAYS AS (`a` > 2) VIRTUAL
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 insert into t1 (a) values (1),(3);
 select * from t1;
@@ -522,5 +522,25 @@ Warning	1292	Incorrect datetime value: 'x'
 Warning	1292	Incorrect datetime value: 'root@localhost'
 drop table t1;
 #
+# CONTEXT_ANALYSIS_ONLY_VCOL_EXPR
+#
+create table t1 (c1 char(1) character set ucs2 collate ucs2_test_ci,
+v1 char(1) character set ucs2 collate ucs2_test_ci as (c1),
+v2 int as (c1 = 'b'),
+v3 int as (v1 = 'b'));
+insert into t1 (c1) values ('a');
+select * from t1 where v1 = 'b';
+c1	v1	v2	v3
+a	a	1	1
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` char(1) CHARACTER SET ucs2 COLLATE ucs2_test_ci DEFAULT NULL,
+  `v1` char(1) CHARACTER SET ucs2 GENERATED ALWAYS AS (`c1`) VIRTUAL,
+  `v2` int(11) GENERATED ALWAYS AS (`c1` = 'b') VIRTUAL,
+  `v3` int(11) GENERATED ALWAYS AS (`v1` = 'b') VIRTUAL
+) ENGINE=MyISAM DEFAULT CHARSET=latin1
+drop table t1;
+#
 # End of 10.2 tests
 #

mysql-test/suite/vcol/t/vcol_misc.opt

+--character-sets-dir=$MYSQL_TEST_DIR/std_data/ldml/

mysql-test/suite/vcol/t/vcol_misc.test

@@ -496,6 +496,21 @@ insert into t1(b) values ('2022-03-17 14:55:37');
 select 1 from t1 x natural join t1;
 drop table t1;
 
+--echo #
+--echo # CONTEXT_ANALYSIS_ONLY_VCOL_EXPR
+--echo #
+
+--source include/have_ucs2.inc
+create table t1 (c1 char(1) character set ucs2 collate ucs2_test_ci,
+                 v1 char(1) character set ucs2 collate ucs2_test_ci as (c1),
+                 v2 int as (c1 = 'b'),
+                 v3 int as (v1 = 'b'));
+insert into t1 (c1) values ('a');
+select * from t1 where v1 = 'b';
+show create table t1;
+drop table t1;
+
 --echo #
 --echo # End of 10.2 tests
 --echo #
+

sql/item.h

@@ -5807,10 +5807,18 @@ class Item_cache: public Item_basic_constant,
     }
     return mark_unsupported_function("cache", arg, VCOL_IMPOSSIBLE);
   }
+  bool fix_fields(THD *thd, Item **ref)
+  {
+    fixed= 1;
+    if (example && !example->fixed)
+      return example->fix_fields(thd, ref);
+    return 0;
+  }
   void cleanup()
   {
     clear();
     Item_basic_constant::cleanup();
+    fixed= 0;
   }
   /**
      Check if saved item has a non-NULL value.

sql/sql_lex.cc

@@ -193,7 +193,6 @@ init_lex_with_single_table(THD *thd, TABLE *table, LEX *lex)
     return TRUE;
   context->resolve_in_table_list_only(table_list);
   lex->use_only_table_context= TRUE;
-  lex->context_analysis_only|= CONTEXT_ANALYSIS_ONLY_VCOL_EXPR;
   select_lex->cur_pos_in_select_list= UNDEF_POS;
   table->map= 1; //To ensure correct calculation of const item
   table_list->table= table;