From 1c923367988687920b05e99bc062a6b4982d03a9 Mon Sep 17 00:00:00 2001
From: WithoutPants <53250216+WithoutPants@users.noreply.github.com>
Date: Tue, 25 Oct 2022 10:57:37 +1100
Subject: [PATCH] Fix symlink size calculation (#3046)

---
 pkg/file/fs.go   |  5 +++++
 pkg/file/scan.go | 16 +++++++++++++++-
 pkg/file/zip.go  |  6 +++++-
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/pkg/file/fs.go b/pkg/file/fs.go
index 45d650fdf..8c09b0fe9 100644
--- a/pkg/file/fs.go
+++ b/pkg/file/fs.go
@@ -22,6 +22,7 @@ func (o *fsOpener) Open() (io.ReadCloser, error) {
 
 // FS represents a file system.
 type FS interface {
+	Stat(name string) (fs.FileInfo, error)
 	Lstat(name string) (fs.FileInfo, error)
 	Open(name string) (fs.ReadDirFile, error)
 	OpenZip(name string) (*ZipFS, error)
@@ -30,6 +31,10 @@ type FS interface {
 // OsFS is a file system backed by the OS.
 type OsFS struct{}
 
+func (f *OsFS) Stat(name string) (fs.FileInfo, error) {
+	return os.Stat(name)
+}
+
 func (f *OsFS) Lstat(name string) (fs.FileInfo, error) {
 	return os.Lstat(name)
 }
diff --git a/pkg/file/scan.go b/pkg/file/scan.go
index 47961fd79..358ff7a27 100644
--- a/pkg/file/scan.go
+++ b/pkg/file/scan.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
+	"os"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -210,6 +211,19 @@ func (s *scanJob) queueFileFunc(ctx context.Context, f FS, zipFile *scanFile) fs
 			return fmt.Errorf("reading info for %q: %w", path, err)
 		}
 
+		var size int64
+
+		// #2196/#3042 - replace size with target size if file is a symlink
+		if info.Mode()&os.ModeSymlink == os.ModeSymlink {
+			targetInfo, err := f.Stat(path)
+			if err != nil {
+				return fmt.Errorf("reading info for symlink %q: %w", path, err)
+			}
+			size = targetInfo.Size()
+		} else {
+			size = info.Size()
+		}
+
 		if !s.acceptEntry(ctx, path, info) {
 			if info.IsDir() {
 				return fs.SkipDir
@@ -225,7 +239,7 @@ func (s *scanJob) queueFileFunc(ctx context.Context, f FS, zipFile *scanFile) fs
 				},
 				Path:     path,
 				Basename: filepath.Base(path),
-				Size:     info.Size(),
+				Size:     size,
 			},
 			fs:   f,
 			info: info,
diff --git a/pkg/file/zip.go b/pkg/file/zip.go
index f610b8b1c..3cf4a819c 100644
--- a/pkg/file/zip.go
+++ b/pkg/file/zip.go
@@ -65,7 +65,7 @@ func (f *ZipFS) rel(name string) (string, error) {
 	return relName, nil
 }
 
-func (f *ZipFS) Lstat(name string) (fs.FileInfo, error) {
+func (f *ZipFS) Stat(name string) (fs.FileInfo, error) {
 	reader, err := f.Open(name)
 	if err != nil {
 		return nil, err
@@ -75,6 +75,10 @@ func (f *ZipFS) Lstat(name string) (fs.FileInfo, error) {
 	return reader.Stat()
 }
 
+func (f *ZipFS) Lstat(name string) (fs.FileInfo, error) {
+	return f.Stat(name)
+}
+
 func (f *ZipFS) OpenZip(name string) (*ZipFS, error) {
 	return nil, errZipFSOpenZip
 }