From 7428e47ebc0bb44ce453e3b43cc7f16077bba421 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Fri, 25 Sep 2020 18:32:31 +0100
Subject: [PATCH] local: fix sizes and syncing with --links option on Windows -
 fixes #4581

Before this change rclone returned the size from the Stat call of the
link. On Windows this reads as 0 always, however on unix it reads as
the length of the text in the link. This caused errors like this when
syncing:

    Failed to copy: corrupted on transfer: sizes differ 0 vs 13

This change causes Windows platforms to read the link and use that as
the size of the link instead of 0 which fixes the problem.
---
 backend/local/local.go               |  9 +++++++++
 backend/local/local_internal_test.go | 11 +----------
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/backend/local/local.go b/backend/local/local.go
index d785fee85..a4a45cd91 100644
--- a/backend/local/local.go
+++ b/backend/local/local.go
@@ -1231,6 +1231,15 @@ func (o *Object) setMetadata(info os.FileInfo) {
 	o.modTime = info.ModTime()
 	o.mode = info.Mode()
 	o.fs.objectMetaMu.Unlock()
+	// On Windows links read as 0 size so set the correct size here
+	if runtime.GOOS == "windows" && o.translatedLink {
+		linkdst, err := os.Readlink(o.path)
+		if err != nil {
+			fs.Errorf(o, "Failed to read link size: %v", err)
+		} else {
+			o.size = int64(len(linkdst))
+		}
+	}
 }
 
 // Stat an Object into info
diff --git a/backend/local/local_internal_test.go b/backend/local/local_internal_test.go
index abdd74dad..f5e651398 100644
--- a/backend/local/local_internal_test.go
+++ b/backend/local/local_internal_test.go
@@ -6,7 +6,6 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"runtime"
 	"testing"
 	"time"
 
@@ -89,9 +88,6 @@ func TestSymlink(t *testing.T) {
 
 	// Object viewed as symlink
 	file2 := fstest.NewItem("symlink.txt"+linkSuffix, "file.txt", modTime2)
-	if runtime.GOOS == "windows" {
-		file2.Size = 0 // symlinks are 0 length under Windows
-	}
 
 	// Object viewed as destination
 	file2d := fstest.NewItem("symlink.txt", "hello", modTime1)
@@ -121,9 +117,6 @@ func TestSymlink(t *testing.T) {
 	// Create a symlink
 	modTime3 := fstest.Time("2002-03-03T04:05:10.123123123Z")
 	file3 := r.WriteObjectTo(ctx, r.Flocal, "symlink2.txt"+linkSuffix, "file.txt", modTime3, false)
-	if runtime.GOOS == "windows" {
-		file3.Size = 0 // symlinks are 0 length under Windows
-	}
 	fstest.CheckListingWithPrecision(t, r.Flocal, []fstest.Item{file1, file2, file3}, nil, fs.ModTimeNotSupported)
 	if haveLChtimes {
 		fstest.CheckItems(t, r.Flocal, file1, file2, file3)
@@ -142,9 +135,7 @@ func TestSymlink(t *testing.T) {
 	o, err := r.Flocal.NewObject(ctx, "symlink2.txt"+linkSuffix)
 	require.NoError(t, err)
 	assert.Equal(t, "symlink2.txt"+linkSuffix, o.Remote())
-	if runtime.GOOS != "windows" {
-		assert.Equal(t, int64(8), o.Size())
-	}
+	assert.Equal(t, int64(8), o.Size())
 
 	// Check that NewObject doesn't see the non suffixed version
 	_, err = r.Flocal.NewObject(ctx, "symlink2.txt")