When stopping playback, turn off the hold pedal.

This ensures that the pedal doesn't remain active when resuming playback, and also stops playback immediately instead of letting notes ring out if a "let ring" was active.

Fixes: #337

CHANGELOG.md

@@ -11,6 +11,7 @@ Thanks to the following contributors who worked on this release:
 ### Changed
 
 ### Fixed
+- Fixed an issue where stopping MIDI playback while a "let ring" was active could incorrectly keep the "let ring" active when restarting playback from the beginning (#337).
 
 ## [Alpha 15] - 2021-07-24
 

source/audio/midioutputdevice.cpp

@@ -76,6 +76,9 @@ MidiOutputDevice::stopAllNotes()
     for (uint8_t channel = 0; channel < Midi::NUM_MIDI_CHANNELS_PER_PORT;
          ++channel)
     {
+        // Turn off the pedal in case a "let ring" event was active.
+        sendMidiMessage(ControlChange + channel, HoldPedal, 0);
+        // Stop all notes.
         sendMidiMessage(ControlChange + channel, AllNotesOff, 0);
     }
 }