[tor-bugs] #15493 [Tor Browser]: Redirects sometimes seem to break circuit status UI

[Tor Bug Tracker & Wiki]

#15493: Redirects sometimes seem to break circuit status UI
-----------------------------+------------------------------------------
     Reporter:  mikeperry    |      Owner:  gk
         Type:  defect       |     Status:  needs_review
     Priority:  normal       |  Milestone:
    Component:  Tor Browser  |    Version:
   Resolution:               |   Keywords:  tbb-circuit-display, tbb-5.0
Actual Points:               |  Parent ID:
       Points:               |
-----------------------------+------------------------------------------
Changes (by arthuredelstein):

 * status:  needs_information => needs_review


Comment:

 Replying to [comment:8 gk]:
 > The problem for the majority of the failures I've seen is that watching
 for the STREAM event is racing with updating the circuit display resulting
 sometimes in logs like the following:
 > {{{
 > [06-12 08:09:29] Torbutton INFO: updating circuit display
 > }}}
 > This is right at the beginning of `updateCircuitDisplay()`
 > {{{
 > [06-12 08:09:29] Torbutton INFO: got credentials zeit.de:2
 > }}}
 > This got logged right at the beginning of the `if (credentials)` block
 in the same function; but we don't have something for `nodeData` yet as
 `credentialsToNodeDataMap` is not ready yet, hence
 > {{{
 > [06-12 08:09:29] Torbutton INFO: about to show the display with:
 undefined
 > }}}
 > which is logged by
 > {{{
 >     logger.eclog(3, "about to show the display with: " + (credentials &&
 nodeData));
 > }}}
 > immediately before `showCircuitDisplay()` is called.
 > Finally, `credentialsToNodeDataMap` gets updated:
 > {{{
 > [06-12 08:09:29] Torbutton INFO: udpating nodeDataForCircuit
 > }}}
 > This got logged in the `if (credentials)` block after STREAM SENTCONNECT
 arrived.

 Thanks for tracking that down. Here's a possible fix for review:
 https://github.com/arthuredelstein/torbutton/commit/15493

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/15493#comment:10>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online