fixup! Better support for merging UNION routes that use IN conditions.

Signed-off-by: Arthur Schreiber <[email protected]>

Author: arthurschreiber

go/vt/vtgate/planbuilder/operators/route_planning.go

@@ -478,20 +478,20 @@ func gen4ValuesEqual(ctx *plancontext.PlanningContext, a, b []sqlparser.Expr) (b
 			return false, nil
 		}
 		if c != nil {
-			conditions = append(conditions, *c)
+			conditions = append(conditions, c...)
 		}
 	}
 	return true, conditions
 }
 
-func gen4ValEqual(ctx *plancontext.PlanningContext, a, b sqlparser.Expr) (bool, *engine.Condition) {
+func gen4ValEqual(ctx *plancontext.PlanningContext, a, b sqlparser.Expr) (bool, []engine.Condition) {
 	switch a := a.(type) {
 	case sqlparser.ValTuple:
 		if b, ok := b.(sqlparser.ValTuple); ok {
 			return gen4ValuesEqual(ctx, a, b)
 		}
 
-		return false
+		return false, nil
 
 	case *sqlparser.ColName:
 		if b, ok := b.(*sqlparser.ColName); ok {
@@ -525,7 +525,7 @@ func gen4ValEqual(ctx *plancontext.PlanningContext, a, b sqlparser.Expr) (bool,
 		}
 
 		return aVal.Type == bVal.Type && bytes.Equal(aVal.Value, bVal.Value),
-			&engine.Condition{A: a.Name, B: b.Name}
+			[]engine.Condition{engine.Condition{A: a.Name, B: b.Name}}
 
 	case *sqlparser.Literal:
 		b, ok := b.(*sqlparser.Literal)