diff -r 3637a0d06fe1 -r 6108b1751c1b src/Pure/Tools/server.scala
--- a/src/Pure/Tools/server.scala	Mon Oct 17 14:11:59 2022 +0200
+++ b/src/Pure/Tools/server.scala	Mon Oct 17 14:24:35 2022 +0200
@@ -173,7 +173,7 @@
         writer_lock = out_lock)
 
     def read_password(password: String): Boolean =
-      try { Byte_Message.read_line(in).map(_.text) == Some(password) }
+      try { Byte_Message.read_line(in).map(_.text).contains(password) }
       catch { case _: IOException => false }
 
     def read_line_message(): Option[String] =