Merge pull request #1200 from silx-kit/ID21_bug

Reset _ROIImageDict if the size is incompatible with the generated image shape

Author: sergey-yaroslavtsev

src/PyMca5/PyMcaGui/pymca/QStackWidget.py

@@ -298,6 +298,8 @@ def setStack(self, *var, **kw):
                 self._stack.data = self._stack.data.reshape(shape[0], shape[1], oldshape[2])
                 self.stackWidget.setImageData(None)
                 self.roiWidget.setImageData(None)
+                # make sure old ROI images are not used
+                self._ROIImageDict["ROI"] = None
                 StackBase.StackBase.setStack(self, self._stack, **kw)
         if self._mcaMax is not None:
             self.addMcaMaxButton.show()