1 files changed, 39 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/errors/is_go112.go b/vendor/google.golang.org/protobuf/internal/errors/is_go112.go
new file mode 100644
index 000000000..f90e909b3
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/internal/errors/is_go112.go
@@ -0,0 +1,39 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build !go1.13
+
+package errors
+
+import "reflect"
+
+// Is is a copy of Go 1.13's errors.Is for use with older Go versions.
+func Is(err, target error) bool {
+	if target == nil {
+		return err == target
+	}
+
+	isComparable := reflect.TypeOf(target).Comparable()
+	for {
+		if isComparable && err == target {
+			return true
+		}
+		if x, ok := err.(interface{ Is(error) bool }); ok && x.Is(target) {
+			return true
+		}
+		if err = unwrap(err); err == nil {
+			return false
+		}
+	}
+}
+
+func unwrap(err error) error {
+	u, ok := err.(interface {
+		Unwrap() error
+	})
+	if !ok {
+		return nil
+	}
+	return u.Unwrap()
+}