MDEV-28437: Assertion `!eliminated' failed: Part #2

In SELECT_LEX::update_used_tables(),
do not run the loop setting tl->table->maybe_null
when tl is an eliminated table

(Rationale: First, with current table elimination, tl already
 has maybe_null=1. Second, one should not care what flags
 eliminated tables had)

Author: spetrunia

sql/sql_lex.cc

@@ -4219,16 +4219,20 @@ void SELECT_LEX::update_used_tables()
   while ((tl= ti++))
   {
     TABLE_LIST *embedding= tl;
-    do
+    if (!is_eliminated_table(join->eliminated_tables, tl))
     {
-      bool maybe_null;
-      if ((maybe_null= MY_TEST(embedding->outer_join)))
+      do
       {
-	tl->table->maybe_null= maybe_null;
-        break;
+        bool maybe_null;
+        if ((maybe_null= MY_TEST(embedding->outer_join)))
+        {
+          tl->table->maybe_null= maybe_null;
+          break;
+        }
       }
+      while ((embedding= embedding->embedding));
     }
-    while ((embedding= embedding->embedding));
+
     if (tl->on_expr && !is_eliminated_table(join->eliminated_tables, tl))
     {
       tl->on_expr->update_used_tables();