From 842887982c7f53aa6c48f1ab300c9eb42476dad3 Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Thu, 20 Jan 2022 10:39:41 +0000
Subject: [PATCH] Migrate old style tokens to new style because element-web
 doesn't soft-logoout on 4xx errors on /sync

---
 syncapi/sync/requestpool.go | 2 +-
 syncapi/types/types.go      | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/syncapi/sync/requestpool.go b/syncapi/sync/requestpool.go
index 2eb50cd7f..ca35951a0 100644
--- a/syncapi/sync/requestpool.go
+++ b/syncapi/sync/requestpool.go
@@ -142,7 +142,7 @@ func (rp *RequestPool) OnIncomingSyncRequest(req *http.Request, device *userapi.
 	if err != nil {
 		if err == types.ErrMalformedSyncToken {
 			return util.JSONResponse{
-				Code: http.StatusUnauthorized,
+				Code: http.StatusBadRequest,
 				JSON: jsonerror.InvalidArgumentValue(err.Error()),
 			}
 		}
diff --git a/syncapi/types/types.go b/syncapi/types/types.go
index 1e5f711e3..68c308d83 100644
--- a/syncapi/types/types.go
+++ b/syncapi/types/types.go
@@ -273,6 +273,9 @@ func NewStreamTokenFromString(tok string) (token StreamingToken, err error) {
 		err = ErrMalformedSyncToken
 		return
 	}
+	// Migration: Remove everything after and including '.' - we previously had tokens like:
+	// s478_0_0_0_0_13.dl-0-2 but we have now removed partitioned stream positions
+	tok = strings.Split(tok, ".")[0]
 	parts := strings.Split(tok[1:], "_")
 	var positions [7]StreamPosition
 	for i, p := range parts {