Reset Session ID on login (#18018) (#18041)

Backport #18018

When logging in the SessionID should be reset and the session cleaned up.

Also logs the user in on completion of linking account

Signed-off-by: Andrew Thornton <art27@cantab.net>

modules/session/store.go

@@ -4,9 +4,21 @@
 
 package session
 
+import (
+	"net/http"
+
+	"gitea.com/go-chi/session"
+)
+
 // Store represents a session store
 type Store interface {
 	Get(interface{}) interface{}
 	Set(interface{}, interface{}) error
 	Delete(interface{}) error
 }
+
+// RegenerateSession regenerates the underlying session and returns the new store
+func RegenerateSession(resp http.ResponseWriter, req *http.Request) (Store, error) {
+	s, err := session.RegenerateSession(resp, req)
+	return s, err
+}