From 7f18ac8f1663c6101c57c9316acaca49c5363261 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Mon, 26 Feb 2024 09:28:58 +1100
Subject: [PATCH] Add BEP 47 extended file attributes fields

---
 metainfo/bep47.go    | 8 ++++++++
 metainfo/fileinfo.go | 8 ++++++--
 metainfo/info.go     | 5 +++--
 3 files changed, 17 insertions(+), 4 deletions(-)
 create mode 100644 metainfo/bep47.go

diff --git a/metainfo/bep47.go b/metainfo/bep47.go
new file mode 100644
index 00000000..884d88d6
--- /dev/null
+++ b/metainfo/bep47.go
@@ -0,0 +1,8 @@
+package metainfo
+
+// See BEP 47. This is common to both Info and FileInfo.
+type ExtendedFileAttrs struct {
+	Attr        string   `bencode:"attr,omitempty"`
+	SymlinkPath []string `bencode:"symlink path,omitempty"`
+	Sha1        string   `bencode:"sha1,omitempty"`
+}
diff --git a/metainfo/fileinfo.go b/metainfo/fileinfo.go
index 2a5ea01d..894018c1 100644
--- a/metainfo/fileinfo.go
+++ b/metainfo/fileinfo.go
@@ -4,9 +4,13 @@ import "strings"
 
 // Information specific to a single file inside the MetaInfo structure.
 type FileInfo struct {
-	Length   int64    `bencode:"length"` // BEP3
-	Path     []string `bencode:"path"`   // BEP3
+	// BEP3. With BEP 47 this can be optional, but we have no way to describe that without breaking
+	// the API.
+	Length   int64    `bencode:"length"`
+	Path     []string `bencode:"path"` // BEP3
 	PathUtf8 []string `bencode:"path.utf-8,omitempty"`
+
+	ExtendedFileAttrs
 }
 
 func (fi *FileInfo) DisplayPath(info *Info) string {
diff --git a/metainfo/info.go b/metainfo/info.go
index 5eedfa3b..b5e4d6e1 100644
--- a/metainfo/info.go
+++ b/metainfo/info.go
@@ -17,8 +17,9 @@ type Info struct {
 	Pieces      []byte `bencode:"pieces"`       // BEP3
 	Name        string `bencode:"name"`         // BEP3
 	NameUtf8    string `bencode:"name.utf-8,omitempty"`
-	Length      int64  `bencode:"length,omitempty"`  // BEP3, mutually exclusive with Files
-	Private     *bool  `bencode:"private,omitempty"` // BEP27
+	Length      int64  `bencode:"length,omitempty"` // BEP3, mutually exclusive with Files
+	ExtendedFileAttrs
+	Private *bool `bencode:"private,omitempty"` // BEP27
 	// TODO: Document this field.
 	Source string     `bencode:"source,omitempty"`
 	Files  []FileInfo `bencode:"files,omitempty"` // BEP3, mutually exclusive with Length
-- 
2.48.1