MDEV-32082 Server crash in find_field_in_table

Attempt to resolve FOR SYSTEM_TIME expression as field for derived
table is done before derived table is fully prepared, so we fail on
assertion that table_list->table is missing.

Actually Vers_history_point::resolve_unit() is done under the call of
mysql_derived_prepare() itself (sql_derived.cc:824) and the table is
assigned later at 867.

The fix disables unit resolution for field type in FOR SYSTEM_TIME
expression as it does a little sense in any case: making historical
queries based on variable field values produces the result of multiple
time points.

fix_fields_if_needed() in resolve_units() was introduced by 46be3198

mysql-test/suite/versioning/r/select.result

@@ -444,7 +444,7 @@ create or replace table t1 (x int) with system versioning;
 select * from t1 for system_time as of current_timestamp;
 x
 select * from t1 for system_time as of now;
-ERROR 42S22: Unknown column 'now' in 'FOR SYSTEM_TIME'
+ERROR HY000: Illegal parameter data type now for operation 'FOR SYSTEM_TIME'
 ### Issue #405, NATURAL JOIN failure
 create or replace table t1 (a int) with system versioning;
 create or replace table t2 (b int);
@@ -708,3 +708,12 @@ No	A	B	C	D
 32	1	1	1	1
 33	1	1	1	1
 34	1	1	1	1
+#
+# MDEV-32082 Server crash in find_field_in_table
+#
+create table t0 (c0 int) with system versioning;
+select x0 from (
+select c0 x0 from t0
+) for system_time as of nowasdf deriv;
+ERROR HY000: Illegal parameter data type nowasdf for operation 'FOR SYSTEM_TIME'
+drop table t0;

mysql-test/suite/versioning/t/select.test

@@ -307,7 +307,7 @@ select * from t1 where (a, 2) in ((1, 1), (2, 2)) and b = 1;
 --echo ### Issue #398, NOW is now non-magic
 create or replace table t1 (x int) with system versioning;
 select * from t1 for system_time as of current_timestamp;
---error ER_BAD_FIELD_ERROR
+--error ER_ILLEGAL_PARAMETER_DATA_TYPE_FOR_OPERATION
 select * from t1 for system_time as of now;
 
 --echo ### Issue #405, NATURAL JOIN failure
@@ -471,4 +471,14 @@ drop tables x, x_p;
 
 call verify_trt_dummy(34);
 
+--echo #
+--echo # MDEV-32082 Server crash in find_field_in_table
+--echo #
+create table t0 (c0 int) with system versioning;
+--error ER_ILLEGAL_PARAMETER_DATA_TYPE_FOR_OPERATION
+select x0 from (
+  select c0 x0 from t0
+) for system_time as of nowasdf deriv;
+drop table t0;
+
 -- source suite/versioning/common_finish.inc

sql/table.cc

@@ -9965,6 +9965,11 @@ bool Vers_history_point::resolve_unit(THD *thd)
 {
   if (!item)
     return false;
+  if (item->real_type() == Item::FIELD_ITEM)
+  {
+    bad_expression_data_type_error(item->full_name());
+    return true;
+  }
   if (item->fix_fields_if_needed(thd, &item))
     return true;
   return item->this_item()->real_type_handler()->