From 8c9a47cff8e74fdd80f1905e3f4f8e51fbaac18d Mon Sep 17 00:00:00 2001
From: Eduard Bagdasaryan <eduard.bagdasaryan@measurement-factory.com>
Date: Thu, 9 Jul 2020 15:41:23 +0300
Subject: [PATCH] Reset the connection establishment 'state' flags on a general
 error

... such as an exception caught in advanceDestination().

This is an old bug: I assume it can lead to an assertion in
establishTunnelThruProxy() if another destination is being attempted
after the previous failure.
---
 src/tunnel.cc | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/tunnel.cc b/src/tunnel.cc
index 63bca37985..c9365ff9fd 100644
--- a/src/tunnel.cc
+++ b/src/tunnel.cc
@@ -272,6 +272,8 @@ private:
     /// server connection is still in use
     bool usingDestination() const;
 
+    void resetStepFlags();
+
     /// details of the "last tunneling attempt" failure (if it failed)
     ErrorState *savedError = nullptr;
 
@@ -1195,6 +1197,7 @@ TunnelStateData::advanceDestination(const char *stepDescription, const Comm::Con
         closePendingConnection(conn, "connection preparation exception");
         if (!savedError)
             saveError(new ErrorState(ERR_CANNOT_FORWARD, Http::scInternalServerError, request.getRaw(), al));
+        resetStepFlags();
         retryOrBail(stepDescription);
     }
 }
@@ -1317,6 +1320,14 @@ TunnelStateData::usingDestination() const
     return securingConnectionToPeer || waitingForConnectExchange || Comm::IsConnOpen(server.conn);
 }
 
+void
+TunnelStateData::resetStepFlags()
+{
+    assert(!Comm::IsConnOpen(server.conn));
+    securingConnectionToPeer = false;
+    waitingForConnectExchange = false;
+}
+
 /// remembers an error to be used if there will be no more connection attempts
 void
 TunnelStateData::saveError(ErrorState *error)
-- 
2.47.3