From 20995f627422a3dce2039f06b5dfe1dc0ca174c6 Mon Sep 17 00:00:00 2001
From: Jannis Andrija Schnitzer <jannis@schnitzer.im>
Date: Mon, 8 Apr 2019 07:31:59 +0000
Subject: [PATCH] archive/zip: use Modified in FileHeader.FileInfo
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The Modified field allows representation of extended timestamps, which provide more accuracy than the legacy MS-DOS timestamps.
The FileInfo method provides an implementation of the os.FileInfo interface for files inside archives.

With this change, we make FileInfo use the Modified field, if present, to return more detailed timestamps from its ModTime method.

Fixes #28350

Change-Id: Ia31b5b871a3e61df38a3a1325787ae23ea0b8088
GitHub-Last-Rev: 13e94be3f8ba58717911354146670fc2bc594692
GitHub-Pull-Request: golang/go#28352
Reviewed-on: https://go-review.googlesource.com/c/go/+/144382
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
---
 src/archive/zip/struct.go   | 13 ++++++++----
 src/archive/zip/zip_test.go | 41 +++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/src/archive/zip/struct.go b/src/archive/zip/struct.go
index bd637d185b..686e79781a 100644
--- a/src/archive/zip/struct.go
+++ b/src/archive/zip/struct.go
@@ -154,10 +154,15 @@ func (fi headerFileInfo) Size() int64 {
 	}
 	return int64(fi.fh.UncompressedSize)
 }
-func (fi headerFileInfo) IsDir() bool        { return fi.Mode().IsDir() }
-func (fi headerFileInfo) ModTime() time.Time { return fi.fh.ModTime() }
-func (fi headerFileInfo) Mode() os.FileMode  { return fi.fh.Mode() }
-func (fi headerFileInfo) Sys() interface{}   { return fi.fh }
+func (fi headerFileInfo) IsDir() bool { return fi.Mode().IsDir() }
+func (fi headerFileInfo) ModTime() time.Time {
+	if fi.fh.Modified.IsZero() {
+		return fi.fh.ModTime()
+	}
+	return fi.fh.Modified.UTC()
+}
+func (fi headerFileInfo) Mode() os.FileMode { return fi.fh.Mode() }
+func (fi headerFileInfo) Sys() interface{}  { return fi.fh }
 
 // FileInfoHeader creates a partially-populated FileHeader from an
 // os.FileInfo.
diff --git a/src/archive/zip/zip_test.go b/src/archive/zip/zip_test.go
index 3d5c759851..efdb5bd044 100644
--- a/src/archive/zip/zip_test.go
+++ b/src/archive/zip/zip_test.go
@@ -114,6 +114,47 @@ func TestFileHeaderRoundTrip64(t *testing.T) {
 	testHeaderRoundTrip(fh, uint32max, fh.UncompressedSize64, t)
 }
 
+func TestFileHeaderRoundTripModified(t *testing.T) {
+	fh := &FileHeader{
+		Name:             "foo.txt",
+		UncompressedSize: 987654321,
+		Modified:         time.Now().Local(),
+		ModifiedTime:     1234,
+		ModifiedDate:     5678,
+	}
+	fi := fh.FileInfo()
+	fh2, err := FileInfoHeader(fi)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, want := fh2.Modified, fh.Modified.UTC(); got != want {
+		t.Errorf("Modified: got %s, want %s\n", got, want)
+	}
+	if got, want := fi.ModTime(), fh.Modified.UTC(); got != want {
+		t.Errorf("Modified: got %s, want %s\n", got, want)
+	}
+}
+
+func TestFileHeaderRoundTripWithoutModified(t *testing.T) {
+	fh := &FileHeader{
+		Name:             "foo.txt",
+		UncompressedSize: 987654321,
+		ModifiedTime:     1234,
+		ModifiedDate:     5678,
+	}
+	fi := fh.FileInfo()
+	fh2, err := FileInfoHeader(fi)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, want := fh2.ModTime(), fh.ModTime(); got != want {
+		t.Errorf("Modified: got %s, want %s\n", got, want)
+	}
+	if got, want := fi.ModTime(), fh.ModTime(); got != want {
+		t.Errorf("Modified: got %s, want %s\n", got, want)
+	}
+}
+
 type repeatedByte struct {
 	off int64
 	b   byte
-- 
2.50.0