cmd/protoc-gen-go: fix generation of enum defaults

Previously, this call strconv.FormatInt with base 32,
when the intention is to call it with base 10.

Change-Id: I31cdd2415b3a80936cdcdeb5612a486204404ecb
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/331149
Trust: Joe Tsai <joetsai@digital-static.net>
Reviewed-by: Damien Neil <dneil@google.com>

cmd/protoc-gen-go/internal_gengo/main.go

@@ -706,7 +706,7 @@ func fieldDefaultValue(g *protogen.GeneratedFile, f *fileInfo, m *messageInfo, f
 			// If the enum value is declared in a different Go package,
 			// reference it by number since the name may not be correct.
 			// See https://github.com/golang/protobuf/issues/513.
-			return g.QualifiedGoIdent(field.Enum.GoIdent) + "(" + strconv.FormatInt(int64(val.Desc.Number()), 32) + ")"
+			return g.QualifiedGoIdent(field.Enum.GoIdent) + "(" + strconv.FormatInt(int64(val.Desc.Number()), 10) + ")"
 		}
 	default:
 		return "0"

internal/testprotos/enums/enums.proto

@@ -0,0 +1,20 @@
+// Copyright 2021 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.
+
+syntax = "proto2";
+
+package goproto.proto.enums;
+
+option go_package = "google.golang.org/protobuf/internal/testprotos/enums";
+
+enum Enum {
+  DEFAULT = 1337;
+  ZERO = 0;
+  ONE = 1;
+  ELEVENT = 11;
+  SEVENTEEN = 17;
+  THIRTYSEVEN = 37;
+  SIXTYSEVEN = 67;
+  NEGATIVE = -1;
+}