Cherry-pick b327743 with conflicts

go/test/endtoend/vtgate/queries/reference/reference_test.go

@@ -83,6 +83,25 @@ func TestReferenceRouting(t *testing.T) {
 		`[[INT64(0)]]`,
 	)
 
+	t.Run("Complex reference query", func(t *testing.T) {
+		utils.SkipIfBinaryIsBelowVersion(t, 20, "vtgate")
+		// Verify a complex query using reference tables with a left join having a derived table with an order by clause works as intended.
+		utils.AssertMatches(
+			t,
+			conn,
+			`SELECT t.id FROM (
+                        SELECT zd.id, zd.zip_id
+                        FROM `+shardedKeyspaceName+`.zip_detail AS zd
+                        WHERE zd.id IN (2)
+                        ORDER BY zd.discontinued_at
+                        LIMIT 1
+                ) AS t
+                LEFT JOIN `+shardedKeyspaceName+`.zip_detail AS t0 ON t.zip_id = t0.zip_id
+                ORDER BY t.id`,
+			`[[INT64(2)]]`,
+		)
+	})
+
 	// UPDATE should route an unqualified zip_detail to unsharded keyspace.
 	utils.Exec(t, conn,
 		"UPDATE zip_detail SET discontinued_at = NULL WHERE id = 2")

go/vt/vtgate/planbuilder/operators/route.go

@@ -591,7 +591,28 @@ func addColumnToInput(operator ops.Operator, expr *sqlparser.AliasedExpr, addToG
 	case *Limit:
 		return addColumnToInput(op.Source, expr, addToGroupBy)
 	case *Ordering:
+<<<<<<< HEAD
 		return addColumnToInput(op.Source, expr, addToGroupBy)
+=======
+		derivedName, src, added, offset := addMultipleColumnsToInput(ctx, op.Source, reuse, addToGroupBy, exprs)
+		if added {
+			op.Source = src
+		}
+		return derivedName, op, added, offset
+
+	case *LockAndComment:
+		derivedName, src, added, offset := addMultipleColumnsToInput(ctx, op.Source, reuse, addToGroupBy, exprs)
+		if added {
+			op.Source = src
+		}
+		return derivedName, op, added, offset
+
+	case *Horizon:
+		// if the horizon has an alias, then it is a derived table,
+		// we have to add a new projection and can't build on this one
+		return op.Alias, op, false, nil
+
+>>>>>>> b327743a25 (Fix aliasing in routes that have a derived table (#15550))
 	case selectExpressions:
 		if op.isDerived() {
 			// if the only thing we can push to is a derived table,