Fix for bug #24261 "crash when WHERE contains NOT IN ('<negative value>') for unsigned column type"

When calculating a SEL_TREE for the "c_{i-1} < X < c_i" interval, check if the tree returned for the "-inf < X < c_0" interval is NULL

mysql-test/r/func_in.result

@@ -342,4 +342,8 @@ select some_id from t1 where some_id not in(-4,-1,3423534,2342342);
 some_id
 1
 2
+select some_id from t1 where some_id not in('-1', '0');
+some_id
+1
+2
 drop table t1;

mysql-test/t/func_in.test

@@ -231,4 +231,11 @@ insert into t1 values (1),(2);
 select some_id from t1 where some_id not in(2,-1);
 select some_id from t1 where some_id not in(-4,-1,-4);
 select some_id from t1 where some_id not in(-4,-1,3423534,2342342);
+
+#
+# BUG#24261: crash when WHERE contains NOT IN ('<negative value>') for unsigned column type
+#
+
+select some_id from t1 where some_id not in('-1', '0');
+
 drop table t1;

sql/opt_range.cc

@@ -3704,6 +3704,7 @@ static SEL_TREE *get_func_mm_tree(PARAM *param, Item_func *cond_func,
             {
               SEL_ARG *new_interval, *last_val;
               if (((new_interval= tree2->keys[idx])) &&
+                  (tree->keys[idx]) &&
                   ((last_val= tree->keys[idx]->last())))
               {
                 new_interval->min_value= last_val->max_value;