Merge pull request pkg#525 from pkg/document_symlink_packet_weirdness

Document the weirdness of the reversal of arguments to SSH_FXP_SYMLINK

internal/encoding/ssh/filexfer/path_packets.go

@@ -323,7 +323,7 @@ func (p *ReadLinkPacket) UnmarshalPacketBody(buf *Buffer) (err error) {
 //
 // The order of the arguments to the SSH_FXP_SYMLINK method was inadvertently reversed.
 // Unfortunately, the reversal was not noticed until the server was widely deployed.
-// Covered in Section 3.1 of https://github.com/openssh/openssh-portable/blob/master/PROTOCOL
+// Covered in Section 4.1 of https://github.com/openssh/openssh-portable/blob/master/PROTOCOL
 type SymlinkPacket struct {
 	LinkPath   string
 	TargetPath string

packet.go

@@ -522,7 +522,12 @@ func (p *sshFxpRmdirPacket) UnmarshalBinary(b []byte) error {
 }
 
 type sshFxpSymlinkPacket struct {
-	ID         uint32
+	ID uint32
+
+	// The order of the arguments to the SSH_FXP_SYMLINK method was inadvertently reversed.
+	// Unfortunately, the reversal was not noticed until the server was widely deployed.
+	// Covered in Section 4.1 of https://github.com/openssh/openssh-portable/blob/master/PROTOCOL
+
 	Targetpath string
 	Linkpath   string
 }