More compatibility fixes for PyQt 5.5

src/calibre/gui2/library/alternate_views.py

@@ -101,7 +101,7 @@ def drag_data(self):
     selected = self.get_selected_ids()
     ids = ' '.join(map(str, selected))
     md = QMimeData()
-    md.setData('application/calibre+from_library', ids)
+    md.setData('application/calibre+from_library', ids.encode('utf-8'))
     fmt = prefs['output_format']
 
     def url_for_id(i):

src/calibre/gui2/library/delegates.py

@@ -55,11 +55,11 @@ class UpdateEditorGeometry(object):
         # Now get the size of the combo/spinner arrows and add them to the needed width
         if isinstance(editor, (QComboBox, QDateTimeEdit)):
             r = style.subControlRect(QStyle.CC_ComboBox, QStyleOptionComboBox(),
-                                      QStyle.SC_ComboBoxArrow)
+                                      QStyle.SC_ComboBoxArrow, editor)
             new_width += r.width()
         elif isinstance(editor, (QSpinBox, QDoubleSpinBox)):
             r = style.subControlRect(QStyle.CC_SpinBox, QStyleOptionSpinBox(),
-                                  QStyle.SC_SpinBoxUp)
+                                  QStyle.SC_SpinBoxUp, editor)
             new_width += r.width()
 
         # Compute the maximum we can show if we consume the entire viewport

src/calibre/gui2/library/views.py

@@ -1098,7 +1098,7 @@ class DeviceBooksView(BooksView):  # {{{
         rows = self.selectionModel().selectedRows()
         paths = [force_unicode(p, enc=filesystem_encoding) for p in m.paths(rows) if p]
         md = QMimeData()
-        md.setData('application/calibre+from_device', 'dummy')
+        md.setData('application/calibre+from_device', b'dummy')
         md.setUrls([QUrl.fromLocalFile(p) for p in paths])
         drag = QDrag(self)
         drag.setMimeData(md)