Do not create a new loop if it's the same as an existing loop

This works around #11003 in which the adjustment of the spinbox creates a new loop, causing a sudden unexpected seek

src/engine/controls/loopingcontrol.cpp

@@ -1400,16 +1400,20 @@ void LoopingControl::slotBeatLoop(double beats, bool keepStartPoint, bool enable
         return;
     }
 
-    // If resizing an inactive loop by changing beatloop_size,
-    // do not seek to the adjusted loop.
-    newloopInfo.seekMode = (keepStartPoint && (enable || m_bLoopingEnabled))
-            ? LoopSeekMode::Changed
-            : LoopSeekMode::MovedOut;
-
-    m_loopInfo.setValue(newloopInfo);
-    emit loopUpdated(newloopInfo.startPosition, newloopInfo.endPosition);
-    m_pCOLoopStartPosition->set(newloopInfo.startPosition.toEngineSamplePos());
-    m_pCOLoopEndPosition->set(newloopInfo.endPosition.toEngineSamplePos());
+    // Only create a new loop if the start and end position have changed.
+    if (loopInfo.startPosition != newloopInfo.startPosition ||
+            loopInfo.endPosition != newloopInfo.endPosition) {
+        // If resizing an inactive loop by changing beatloop_size,
+        // do not seek to the adjusted loop.
+        newloopInfo.seekMode = (keepStartPoint && (enable || m_bLoopingEnabled))
+                ? LoopSeekMode::Changed
+                : LoopSeekMode::MovedOut;
+
+        m_loopInfo.setValue(newloopInfo);
+        emit loopUpdated(newloopInfo.startPosition, newloopInfo.endPosition);
+        m_pCOLoopStartPosition->set(newloopInfo.startPosition.toEngineSamplePos());
+        m_pCOLoopEndPosition->set(newloopInfo.endPosition.toEngineSamplePos());
+    }
 
     if (enable) {
         setLoopingEnabled(true);