Merge pull request #2992 from ywwg/clone-deck-crash

Fix missing nullptr check.

2 files changed, 6 insertions, 2 deletions

diff --git a/src/engine/sync/enginesync.h b/src/engine/sync/enginesync.h
index 8374d81155..29fc05ff2b 100644
--- a/src/engine/sync/enginesync.h
+++ b/src/engine/sync/enginesync.h
@@ -52,11 +52,13 @@ class EngineSync : public BaseSyncableListener {
     void notifyScratching(Syncable* pSyncable, bool scratching) override;
 
     // Used to pick a sync target for cases where master sync mode is not sufficient.
-    // Guaranteed to pick a Syncable that is a real deck and has an EngineBuffer.
+    // Guaranteed to pick a Syncable that is a real deck and has an EngineBuffer,
+    // but can return nullptr if there are no choices.
     // First choice is master sync, if it's a real deck,
     // then it will fall back to the first playing syncable deck,
     // then it will fall back to the first playing deck,
     // then it will fall back to the first non-playing deck.
+    // If there is literally nothing loaded, returns nullptr.
     Syncable* pickNonSyncSyncTarget(EngineChannel* pDontPick) const;
 
     // Used to test whether changing the rate of a Syncable would change the rate
diff --git a/src/mixer/basetrackplayer.cpp b/src/mixer/basetrackplayer.cpp
index 2058d66d6a..ebd7b70fd3 100644
--- a/src/mixer/basetrackplayer.cpp
+++ b/src/mixer/basetrackplayer.cpp
@@ -525,7 +525,9 @@ TrackPointer BaseTrackPlayerImpl::getLoadedTrack() const {
 
 void BaseTrackPlayerImpl::slotCloneDeck() {
     Syncable* syncable = m_pEngineMaster->getEngineSync()->pickNonSyncSyncTarget(m_pChannel);
-    slotCloneChannel(syncable->getChannel());
+    if (syncable) {
+        slotCloneChannel(syncable->getChannel());
+    }
 }
 
 void BaseTrackPlayerImpl::slotCloneFromGroup(const QString& group) {