Call to sqlx.In on driver.Value with nil value panics

bind.go

@@ -163,7 +163,7 @@ func In(query string, args ...interface{}) (string, []interface{}, error) {
 	for i, arg := range args {
 		if a, ok := arg.(driver.Valuer); ok {
 			var err error
-			arg, err = a.Value()
+			arg, err = callValuerValue(a)
 			if err != nil {
 				return "", nil, err
 			}
@@ -263,3 +263,24 @@ func appendReflectSlice(args []interface{}, v reflect.Value, vlen int) []interfa
 
 	return args
 }
+
+// callValuerValue returns vr.Value(), with one exception:
+// If vr.Value is an auto-generated method on a pointer type and the
+// pointer is nil, it would panic at runtime in the panicwrap
+// method. Treat it like nil instead.
+// Issue 8415.
+//
+// This is so people can implement driver.Value on value types and
+// still use nil pointers to those types to mean nil/NULL, just like
+// string/*string.
+//
+// This function is copied from database/sql/driver package
+// and mirrored in the database/sql package.
+func callValuerValue(vr driver.Valuer) (v driver.Value, err error) {
+	if rv := reflect.ValueOf(vr); rv.Kind() == reflect.Pointer &&
+		rv.IsNil() &&
+		rv.Type().Elem().Implements(reflect.TypeOf((*driver.Valuer)(nil)).Elem()) {
+		return nil, nil
+	}
+	return vr.Value()
+}

sqlx_test.go

@@ -1504,6 +1504,14 @@ func TestIssue197(t *testing.T) {
 	})
 }
 
+type Valuer struct {
+	Val string
+}
+
+func (v Valuer) Value() (driver.Value, error) {
+	return v.Val, nil
+}
+
 func TestIn(t *testing.T) {
 	// some quite normal situations
 	type tr struct {
@@ -1538,6 +1546,24 @@ func TestIn(t *testing.T) {
 		}
 	}
 
+	// nil driver.Valuer
+	t.Run("with nil driver.Valuer", func(t *testing.T) {
+		query := `SELECT * FROM foo WHERE x = ? or y IN (?)`
+		_, _, err := In(query,
+			(*Valuer)(nil), // a non-inited pointer to valuer
+			[]interface{}{
+				"a",                 // a usual value
+				nil,                 // a nil value
+				Valuer{Val: "foo"},  // a Valuer
+				&Valuer{Val: "foo"}, // a pointer to valuer
+				(*Valuer)(nil),      // a non-inited pointer to valuer
+			},
+		)
+		if err != nil {
+			t.Error(err)
+		}
+	})
+
 	// too many bindVars, but no slices, so short circuits parsing
 	// i'm not sure if this is the right behavior;  this query/arg combo
 	// might not work, but we shouldn't parse if we don't need to