From 57e040070c03397ae0396e39348be6691c5f939a Mon Sep 17 00:00:00 2001
From: Paul Licameli <paul.licameli@audacityteam.org>
Date: Fri, 21 Jul 2017 01:39:13 -0400
Subject: [PATCH] Bug1627: Fix infinite recursion of error dialogs, failing
 start scrub

---
 src/toolbars/ControlToolBar.cpp | 7 +++++++
 src/tracks/ui/Scrubbing.cpp     | 8 ++++++++
 2 files changed, 15 insertions(+)

diff --git a/src/toolbars/ControlToolBar.cpp b/src/toolbars/ControlToolBar.cpp
index 98310cf53..fd851c324 100644
--- a/src/toolbars/ControlToolBar.cpp
+++ b/src/toolbars/ControlToolBar.cpp
@@ -709,10 +709,17 @@ int ControlToolBar::PlayPlayRegion(const SelectedRegion &selectedRegion,
 #endif
       }
       else {
+         // Bug1627 (part of it):
+         // infinite error spew when trying to start scrub:
+         // Problem was that the error dialog yields to events,
+         // causing recursion to this function in the scrub timer
+         // handler!  Easy fix, just delay the user alert instead.
+         CallAfter( [=]{
          // Show error message if stream could not be opened
          ShowErrorDialog(this, _("Error"),
                          _("Error opening sound device.\nTry changing the audio host, playback device and the project sample rate."),
                          wxT("http://manual.audacityteam.org/man/faq_errors.html#sound_device"), false);
+         });
       }
    }
 
diff --git a/src/tracks/ui/Scrubbing.cpp b/src/tracks/ui/Scrubbing.cpp
index c1e19dfd3..17a0c32d9 100644
--- a/src/tracks/ui/Scrubbing.cpp
+++ b/src/tracks/ui/Scrubbing.cpp
@@ -421,6 +421,14 @@ bool Scrubber::MaybeStartScrubbing(wxCoord xx)
 
          mPoller->Start(ScrubPollInterval_ms);
       }
+      else if (mScrubToken <= 0) {
+         // Bug1627 (part of it):
+         // infinite error spew when trying to start scrub:
+         // If failed for reasons of audio device problems, do not try
+         // again with repeated timer ticks.
+         mScrubStartPosition = -1;
+         return false;
+      }
 
       // Return true whether we started scrub, or are still waiting to decide.
       return true;