From 1c027f395ef777d099155c0142dd7eff1b7c2f2c Mon Sep 17 00:00:00 2001
From: wmdngngng <wangmingdong@gmail.com>
Date: Thu, 23 Sep 2021 15:34:59 +0000
Subject: [PATCH] cmd/gomobile: fix header padding computation in apk
 generation

fix file data align to 4

Change-Id: Ie88c46521e216b3f83a8dc3495591cd19bce83c6
GitHub-Last-Rev: aebf3cd7ff0d77050659e9269f7eddaeff364eff
GitHub-Pull-Request: golang/mobile#73
Reviewed-on: https://go-review.googlesource.com/c/mobile/+/351789
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Hajime Hoshi <hajimehoshi@gmail.com>
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
---
 cmd/gomobile/writer.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cmd/gomobile/writer.go b/cmd/gomobile/writer.go
index 0f3c29b..8801041 100644
--- a/cmd/gomobile/writer.go
+++ b/cmd/gomobile/writer.go
@@ -115,7 +115,7 @@ func (w *Writer) create(name string) (io.Writer, error) {
 	}
 	const fileHeaderLen = 30 // + filename + extra
 	start := w.offset + fileHeaderLen + len(name)
-	extra := start % 4
+	extra := (-start) & 3
 
 	zipfw, err := w.w.CreateHeader(&zip.FileHeader{
 		Name:  name,