MDEV-16930 Crash when VALUES in derived table contains expressions

This patch always provides columns of the temporary table used for
materialization of a table value constructor with some names.
Before this patch these names were always borrowed from the items
of the first row of the table value constructor. When this row
contained expressions and expressions were not named then it could cause
different kinds of problems. In particular if the TVC is used as the
specification of a derived table this could cause a crash.
The names given to the expressions used in a TVC are the same as those
given to the columns of the result set from the corresponding SELECT.

mysql-test/main/table_value_constr.result

@@ -2154,3 +2154,38 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 3	UNION	t1	ALL	NULL	NULL	NULL	NULL	3	
 NULL	UNION RESULT	<union2,3>	ALL	NULL	NULL	NULL	NULL	NULL	
 drop table t1;
+#
+# MDEV-16930: expression in the first row of TVC specifying derived table
+#
+SELECT 1 + 1, 2, "abc";
+1 + 1	2	abc
+2	2	abc
+SELECT * FROM (SELECT 1 + 1, 2, "abc") t;
+1 + 1	2	abc
+2	2	abc
+WITH cte AS (SELECT 1 + 1, 2, "abc") SELECT * FROM cte;
+1 + 1	2	abc
+2	2	abc
+SELECT 1 + 1, 2, "abc" UNION SELECT 3+4, 3, "abc";
+1 + 1	2	abc
+2	2	abc
+7	3	abc
+CREATE VIEW v1 AS SELECT 1 + 1, 2, "abc";
+SELECT * FROM v1;
+1 + 1	2	abc
+2	2	abc
+DROP VIEW v1;
+VALUES(1 + 1,2,"abc");
+1 + 1	2	abc
+2	2	abc
+SELECT * FROM (VALUES(1 + 1,2,"abc")) t;
+1 + 1	2	abc
+2	2	abc
+PREPARE stmt FROM "SELECT * FROM (VALUES(1 + 1,2,'abc')) t";
+EXECUTE stmt;
+1 + 1	2	abc
+2	2	abc
+EXECUTE stmt;
+1 + 1	2	abc
+2	2	abc
+DEALLOCATE PREPARE stmt;

mysql-test/main/table_value_constr.test

@@ -1104,3 +1104,24 @@ eval $q4;
 eval explain $q4;
 
 drop table t1;
+
+--echo #
+--echo # MDEV-16930: expression in the first row of TVC specifying derived table
+--echo #
+
+SELECT 1 + 1, 2, "abc";
+SELECT * FROM (SELECT 1 + 1, 2, "abc") t;
+WITH cte AS (SELECT 1 + 1, 2, "abc") SELECT * FROM cte; 
+SELECT 1 + 1, 2, "abc" UNION SELECT 3+4, 3, "abc";
+CREATE VIEW v1 AS SELECT 1 + 1, 2, "abc";
+SELECT * FROM v1;
+DROP VIEW v1;
+
+VALUES(1 + 1,2,"abc");
+SELECT * FROM (VALUES(1 + 1,2,"abc")) t;
+PREPARE stmt FROM "SELECT * FROM (VALUES(1 + 1,2,'abc')) t";
+EXECUTE stmt;
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+
+

sql/sql_yacc.yy

@@ -2044,6 +2044,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         preload_list preload_list_or_parts preload_keys preload_keys_parts
         select_item_list select_item values_list no_braces
         opt_limit_clause delete_limit_clause fields opt_values values
+        no_braces_with_names opt_values_with_names values_with_names
         procedure_list procedure_list2 procedure_item
         field_def handler opt_generated_always
         opt_ignore opt_column opt_restrict
@@ -13247,7 +13248,7 @@ insert_values:
 
 values_list:
           values_list ','  no_braces
-        | no_braces
+        | no_braces_with_names
         ;
 
 ident_eq_list:
@@ -13300,11 +13301,31 @@ no_braces:
           }
         ;
 
+no_braces_with_names:
+          '('
+          {
+            if (unlikely(!(Lex->insert_list= new (thd->mem_root) List_item)))
+              MYSQL_YYABORT;
+          }
+          opt_values_with_names ')'
+          {
+            LEX *lex=Lex;
+            if (unlikely(lex->many_values.push_back(lex->insert_list,
+                                                    thd->mem_root)))
+              MYSQL_YYABORT;
+          }
+        ;
+
 opt_values:
           /* empty */ {}
         | values
         ;
 
+opt_values_with_names:
+          /* empty */ {}
+        | values_with_names
+        ;
+
 values:
           values ','  expr_or_default
           {
@@ -13318,6 +13339,25 @@ values:
           }
         ;
 
+values_with_names:
+          values_with_names ','  remember_name expr_or_default remember_end
+          {
+            if (unlikely(Lex->insert_list->push_back($4, thd->mem_root)))
+               MYSQL_YYABORT;
+            // give some name in case of using in table value constuctor (TVC)
+            if (!$4->name.str)
+              $4->set_name(thd, $3, (uint) ($5 - $3), thd->charset());
+           }
+        | remember_name expr_or_default remember_end
+          {
+            if (unlikely(Lex->insert_list->push_back($2, thd->mem_root)))
+               MYSQL_YYABORT;
+            // give some name in case of using in table value constuctor (TVC)
+            if (!$2->name.str)
+              $2->set_name(thd, $1, (uint) ($3 - $1), thd->charset());
+          }
+        ;
+
 expr_or_default:
           expr { $$= $1;}
         | DEFAULT

sql/sql_yacc_ora.yy

@@ -1450,6 +1450,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, size_t *yystacksize);
         assign_to_keycache_parts
         preload_list preload_list_or_parts preload_keys preload_keys_parts
         select_item_list select_item values_list no_braces
+        no_braces_with_names opt_values_with_names values_with_names
         opt_limit_clause delete_limit_clause fields opt_values values
         procedure_list procedure_list2 procedure_item
         field_def handler opt_generated_always
@@ -13402,7 +13403,7 @@ insert_values:
 
 values_list:
           values_list ','  no_braces
-        | no_braces
+        | no_braces_with_names
         ;
 
 ident_eq_list:
@@ -13455,11 +13456,31 @@ no_braces:
           }
         ;
 
+no_braces_with_names:
+          '('
+          {
+            if (unlikely(!(Lex->insert_list= new (thd->mem_root) List_item)))
+              MYSQL_YYABORT;
+          }
+          opt_values_with_names ')'
+          {
+            LEX *lex=Lex;
+            if (unlikely(lex->many_values.push_back(lex->insert_list,
+                                                    thd->mem_root)))
+              MYSQL_YYABORT;
+          }
+        ;
+
 opt_values:
           /* empty */ {}
         | values
         ;
 
+opt_values_with_names:
+          /* empty */ {}
+        | values_with_names
+        ;
+
 values:
           values ','  expr_or_default
           {
@@ -13473,6 +13494,25 @@ values:
           }
         ;
 
+values_with_names:
+          values_with_names ','  remember_name expr_or_default remember_end
+          {
+            if (unlikely(Lex->insert_list->push_back($4, thd->mem_root)))
+               MYSQL_YYABORT;
+            // give some name in case of using in table value constuctor (TVC)
+            if (!$4->name.str)
+              $4->set_name(thd, $3, (uint) ($5 - $3), thd->charset());
+           }
+        | remember_name expr_or_default remember_end
+          {
+            if (unlikely(Lex->insert_list->push_back($2, thd->mem_root)))
+               MYSQL_YYABORT;
+            // give some name in case of using in table value constuctor (TVC)
+            if (!$2->name.str)
+              $2->set_name(thd, $1, (uint) ($3 - $1), thd->charset());
+          }
+        ;
+
 expr_or_default:
           expr { $$= $1;}
         | DEFAULT