Set expressionIsInferred when setting quarterLength directly

Author: jacobtylerwalls

music21/duration.py

@@ -1763,7 +1763,7 @@ def _updateComponents(self):
         '''
         # this update will not be necessary
         self._quarterLengthNeedsUpdating = False
-        if self.linked:
+        if self.linked and self.expressionIsInferred:
             qlc = quarterConversion(self._qtrLength)
             self.components = list(qlc.components)
             if qlc.tuplet is not None:
@@ -2824,6 +2824,7 @@ def _setQuarterLength(self, value: OffsetQLIn):
             if value == 0.0 and self.linked is True:
                 self.clear()
             self._qtrLength = value
+            self.expressionIsInferred = True
             self._componentsNeedUpdating = True
             self._quarterLengthNeedsUpdating = False