Use prep_null_mask_filter to handle nulls in selection mask

datafusion/physical-plan/src/joins/sort_merge_join.rs

@@ -1209,7 +1209,14 @@ impl SMJStream {
                     ) {
                         // The reverse of the selection mask. For the rows not pass join filter above,
                         // we need to join them (left or right) with null rows for outer joins.
-                        let not_mask = compute::not(mask)?;
+                        let not_mask = if mask.null_count() > 0 {
+                            // If the mask contains nulls, we need to use `prep_null_mask_filter` to
+                            // handle the nulls in the mask as false.
+                            compute::not(&compute::prep_null_mask_filter(mask))?
+                        } else {
+                            compute::not(mask)?
+                        };
+
                         let null_joined_batch =
                             compute::filter_record_batch(&output_batch, &not_mask)?;
 

datafusion/sqllogictest/test_files/sort_merge_join.slt

@@ -256,6 +256,16 @@ SELECT * FROM t1 FULL JOIN t2 ON t1_id = t2_id AND t2_int <= t1_int
 44 d 4 44 x 3
 NULL NULL NULL 11 z 3
 NULL NULL NULL 55 w 3
+NULL NULL NULL NULL NULL NULL
+
+# equijoin_left_and_condition_from_both
+query III rowsort
+SELECT t1_id, t1_int, t2_int FROM t1 LEFT JOIN t2 ON t1_id = t2_id AND t1_int >= t2_int
+----
+11 1 NULL
+22 2 1
+33 3 NULL
+44 4 3
 
 statement ok
 DROP TABLE t1;