From 02a33d95042201adfbd6b8c56ef8d71741ac5029 Mon Sep 17 00:00:00 2001
From: Jens-Uwe Mager <jum@anubis.han.de>
Date: Thu, 12 Mar 2020 16:41:52 +0100
Subject: [PATCH 1/2] Added a MergeSession method to ease merging of sessions
 lost due to strict cookies across oauth2 login flows.

---
 data.go | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/data.go b/data.go
index 99ccf08..60c108c 100644
--- a/data.go
+++ b/data.go
@@ -301,6 +301,44 @@ func (s *SessionManager) RenewToken(ctx context.Context) error {
 	return nil
 }
 
+// MergeSession is used to merge in data from a different session in case strict
+// session tokens are lost across an oauth or similar redirect flows. Use Clear()
+// if no values of the new session are to be used.
+func (s *SessionManager) MergeSession(ctx context.Context, token string) error {
+	sd := s.getSessionDataFromContext(ctx)
+
+	b, found, err := s.ContextStore.Find(ctx, token)
+	if err != nil {
+		return err
+	} else if !found {
+		return nil
+	}
+
+	deadline, values, err := s.Codec.Decode(b)
+	if err != nil {
+		return err
+	}
+
+	sd.mu.Lock()
+	defer sd.mu.Unlock()
+
+	// If it is the same session, nothing needs to be done.
+	if sd.token == token {
+		return nil
+	}
+
+	if deadline.After(sd.deadline) {
+		sd.deadline = deadline
+	}
+
+	for k, v := range values {
+		sd.values[k] = v
+	}
+
+	sd.status = Modified
+	return s.ContextStore.Delete(ctx, token)
+}
+
 // Status returns the current status of the session data.
 func (s *SessionManager) Status(ctx context.Context) Status {
 	sd := s.getSessionDataFromContext(ctx)

From fd3404d1a47d8cd4b11908cc988dd948a56aa715 Mon Sep 17 00:00:00 2001
From: Jens-Uwe Mager <jum@anubis.han.de>
Date: Wed, 24 Nov 2021 21:29:39 +0100
Subject: [PATCH 2/2] Adapt to the new *Ctx() methods.

---
 data.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/data.go b/data.go
index 60c108c..8c31560 100644
--- a/data.go
+++ b/data.go
@@ -307,7 +307,7 @@ func (s *SessionManager) RenewToken(ctx context.Context) error {
 func (s *SessionManager) MergeSession(ctx context.Context, token string) error {
 	sd := s.getSessionDataFromContext(ctx)
 
-	b, found, err := s.ContextStore.Find(ctx, token)
+	b, found, err := s.doStoreFind(ctx, token)
 	if err != nil {
 		return err
 	} else if !found {
@@ -336,7 +336,7 @@ func (s *SessionManager) MergeSession(ctx context.Context, token string) error {
 	}
 
 	sd.status = Modified
-	return s.ContextStore.Delete(ctx, token)
+	return s.doStoreDelete(ctx, token)
 }
 
 // Status returns the current status of the session data.