From 9aceb99952fca0d32ce42d97eabb2105d56feaeb Mon Sep 17 00:00:00 2001
From: Fabien Meurillon <fabien@meurillon.org>
Date: Mon, 9 Jul 2018 17:19:11 +0200
Subject: [PATCH] Perform a hard copy if the temporary file cannot be moved

---
 CHANGELOG.md |  9 ++++++++-
 updater.go   | 31 +++++++++++++++++++++++++++++--
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2febcbe..756b401 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,11 +6,18 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [1.0.1]
+
+### Fixed
+
+- Perform a hard copy if the temporary file cannot be moved
+
 ## [1.0.0]
 
 ### Added
 
 - Initial import of the lib, handling simples HTML "file-index" pages
 
-[Unreleased]: https://github.com/FabienM/updater/compare/1.0.0...master
+[Unreleased]: https://github.com/FabienM/updater/compare/1.0.1...master
+[1.0.1]: https://github.com/FabienM/updater/compare/1.0.0...1.0.1
 [1.0.0]: https://github.com/FabienM/updater/tag/1.0.0
\ No newline at end of file
diff --git a/updater.go b/updater.go
index 2d724cc..cd7a191 100644
--- a/updater.go
+++ b/updater.go
@@ -156,8 +156,7 @@ func (u Updater) UpdateTo(build *BuildInfo) error {
 		return err
 	}
 
-	err = os.Rename(tmpPath, path)
-	if err != nil {
+	if err = updateFile(tmpPath, path); err != nil {
 		return fmt.Errorf("cannot move temporary file %s to %s: %s", tmpPath, path, err)
 	}
 
@@ -255,3 +254,31 @@ func (s *buildInfoSorter) Len() int {
 func (s *buildInfoSorter) Swap(i, j int) {
 	s.builds[i], s.builds[j] = s.builds[j], s.builds[i]
 }
+
+func updateFile(src, dst string) error {
+	if err := os.Rename(src, dst); err == nil {
+		return nil
+	}
+
+	in, err := os.Open(src)
+	if err != nil {
+		return err
+	}
+	defer in.Close()
+
+	out, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer out.Close()
+
+	if _, err = io.Copy(out, in); err != nil {
+		return err
+	}
+
+	if err := out.Chmod(0755); err != nil {
+		return err
+	}
+
+	return out.Close()
+}