Bug#35195181 mysqld crash in make_sortkey_from_item

Propagate errors properly when evaluating Items to be sorted by filesort.

Change-Id: Iee76ccedfe764a8d94c593feebd3c8094125b8eb
(cherry picked from commit 57169f5077535283c842bb4caed04024ee8cd05c)

Author: Tor Didriksen

sql/filesort.cc

@@ -1262,6 +1262,9 @@ size_t make_sortkey_from_item(Item *item, Item_result result_type,
       const CHARSET_INFO *cs = item->collation.collation;
 
       String *res = item->val_str(tmp_buffer);
+      if (current_thd->is_error()) {
+        return UINT_MAX;
+      }
       if (res == nullptr)  // Value is NULL.
       {
         assert(item->is_nullable());
@@ -1307,6 +1310,9 @@ size_t make_sortkey_from_item(Item *item, Item_result result_type,
     case INT_RESULT: {
       assert(!is_varlen);
       longlong value = item->int_sort_key();
+      if (current_thd->is_error()) {
+        return UINT_MAX;
+      }
 
       /*
         Note: item->null_value can't be trusted alone here; there are cases
@@ -1356,6 +1362,9 @@ size_t make_sortkey_from_item(Item *item, Item_result result_type,
     case REAL_RESULT: {
       assert(!is_varlen);
       double value = item->val_real();
+      if (current_thd->is_error()) {
+        return UINT_MAX;
+      }
       if (item->null_value) {
         assert(item->is_nullable());
         *null_indicator = 0;