Bug#37651856: Crash after secondary is off. [MYSQL change]

Fix: we need to ensure secondary engine is available

Change-Id: Ib42f2b6d2040441f3e269a213188e5478558480a

Author: Keshav Singh

sql/handler.h

@@ -2121,15 +2121,17 @@ typedef bool (*get_table_statistics_t)(
 
 /**
   Retrieve column_statistics from SE.
-
+  @param THD                      Current THD
   @param db_name                  Name of schema
   @param table_name               Name of table
   @param column_name              Name of column
+  @param rows_in_table            Nrows in table
 
   @returns The statistics if available, empty value otherwise.
 */
 typedef std::optional<ha_column_statistics> (*get_column_statistics_t)(
-    const char *db_name, const char *table_name, const char *column_name);
+    THD *thd, const char *db_name, const char *table_name,
+    const char *column_name, double rows_in_table);
 
 /**
   @brief

sql/join_optimizer/secondary_statistics.cc

@@ -43,9 +43,11 @@ double NumDistinctValues(THD *thd, const Field &field) {
       EligibleSecondaryEngineHandlerton(thd, &ts->secondary_engine);
   if (secondary_engine != nullptr &&
       secondary_engine->get_column_statistics != nullptr) {
+    const auto rows_in_table =
+        static_cast<double>(field.table->file->stats.records);
     auto column_stats = secondary_engine->get_column_statistics(
-        field.table->s->db.str, field.table->s->table_name.str,
-        field.field_name);
+        thd, field.table->s->db.str, field.table->s->table_name.str,
+        field.field_name, rows_in_table);
     if (column_stats.has_value() && column_stats->num_distinct_values > 0) {
       const double distinct_values = column_stats->num_distinct_values;
       if (TraceStarted(thd)) {