Fix QDateTime conversions

- Qt 5.7 doesn't have QDateTime::(from|to)SecsSinceEpoch, so we need to use the
  msecs variant instead.
- We were passing a float which causes a TypeError (rather than being truncated
  to an int) with newer PyQt versions.

qutebrowser/completion/models/miscmodels.py

@@ -223,10 +223,10 @@ def _qdatetime_to_completion_format(qdate):
     if not qdate.isValid():
         ts = 0
     else:
-        ts = qdate.toSecsSinceEpoch()
+        ts = qdate.toMSecsSinceEpoch()
         if ts < 0:
             ts = 0
-    pydate = datetime.datetime.fromtimestamp(ts)
+    pydate = datetime.datetime.fromtimestamp(ts / 1000)
     return pydate.strftime(config.val.completion.timestamp_format)
 
 

tests/unit/completion/test_models.py

@@ -1211,7 +1211,8 @@ def tab_with_history(fake_web_tab, tabbed_browser_stubs, info, monkeypatch):
         entry = mock.Mock(spec=QWebEngineHistoryItem)
         entry.url.return_value = QUrl(url)
         entry.title.return_value = title
-        entry.lastVisited.return_value = QDateTime.fromSecsSinceEpoch(ts)
+        dt = QDateTime.fromMSecsSinceEpoch(int(ts * 1000))
+        entry.lastVisited.return_value = dt
         history.append(entry)
     tab.history._history = mock.Mock(spec=QWebEngineHistory)
     tab.history._history.items.return_value = history