This time, really fix the sorting problem.

src/calibre/gui2/library/__init__.py

@@ -7,4 +7,4 @@ __docformat__ = 'restructuredtext en'
 
 from PyQt4.Qt import Qt
 
-DEFAULT_SORT = ('timestamp', Qt.DescendingOrder)
+DEFAULT_SORT = ('timestamp', False)

src/calibre/gui2/library/models.py

@@ -247,12 +247,13 @@ class BooksModel(QAbstractTableModel): # {{{
         if not self.db:
             return
         self.about_to_be_sorted.emit(self.db.id)
-        ascending = order == Qt.AscendingOrder
+        if not isinstance(order, bool):
+            order = order == Qt.AscendingOrder
         label = self.column_map[col]
-        self.db.sort(label, ascending)
+        self.db.sort(label, order)
         if reset:
             self.reset()
-        self.sorted_on = (label, order == Qt.AscendingOrder)
+        self.sorted_on = (label, order)
         self.sort_history.insert(0, self.sorted_on)
         self.sorting_done.emit(self.db.index)
 

src/calibre/gui2/library/views.py

@@ -165,7 +165,7 @@ class BooksView(QTableView): # {{{
                     partial(self.column_header_context_handler,
                         action='descending', column=col))
             if self._model.sorted_on[0] == col:
-                ac = a if self._model.sorted_on[1] == Qt.AscendingOrder else d
+                ac = a if self._model.sorted_on[1] else d
                 ac.setCheckable(True)
                 ac.setChecked(True)
             if col not in ('ondevice', 'rating', 'inlibrary') and \
@@ -282,13 +282,13 @@ class BooksView(QTableView): # {{{
     def cleanup_sort_history(self, sort_history):
         history = []
         for col, order in sort_history:
+            if not isinstance(order, bool):
+                continue
             if col == 'date':
                 col = 'timestamp'
             if col in self.column_map:
-                if (not history or history[0][0] != col):
+                if (not history or history[-1][0] != col):
                     history.append([col, order])
-                elif isinstance(order, bool) and history[0][1] != order:
-                    history[0][1] = order
         return history
 
     def apply_sort_history(self, saved_history):

src/calibre/library/caches.py

@@ -669,6 +669,9 @@ class ResultCache(SearchQueryParser): # {{{
             fields = [('timestamp', False)]
 
         keyg = SortKeyGenerator(fields, self.field_metadata, self._data)
+        # For efficiency, the key generator returns a plain value if only one
+        # field is in the sort field list. Because the normal cmp function will
+        # always assume asc, we must deal with asc/desc here.
         if len(fields) == 1:
             self._map.sort(key=keyg, reverse=not fields[0][1])
         else:
@@ -697,7 +700,7 @@ class SortKeyGenerator(object):
     def __init__(self, fields, field_metadata, data):
         from calibre.utils.icu import sort_key
         self.field_metadata = field_metadata
-        self.orders = [-1 if x[1] else 1 for x in fields]
+        self.orders = [1 if x[1] else -1 for x in fields]
         self.entries = [(x[0], field_metadata[x[0]]) for x in fields]
         self.library_order = tweaks['title_series_sorting'] == 'library_order'
         self.data = data