Disconnect SignalBlocker after exiting loop.

Otherwise, a second signal emission will still call the functions of the
already garbage-collected SignalBlocker with PyQt5 < 5.3.

The signals could already be disconnected, so the TypeError (older PyQt
versions) or RuntimeError (newer PyQt versions) which is raised in that case is
ignored.

Fixes #69.

Author: The-Compiler

pytestqt/_tests/test_wait_signal.py

@@ -239,3 +239,30 @@ class TestException(Exception):
     with pytest.raises(TestException):
         with func(arg, timeout=10, raising=raising):
             raise TestException
+
+
+@pytest.mark.parametrize('multiple, do_timeout',
+                         [(True, False), (True, True), (False, False), (False, True)])
+def test_wait_twice(qtbot, single_shot, multiple, do_timeout):
+    """
+    https://github.com/pytest-dev/pytest-qt/issues/69
+    """
+    signaller = Signaller()
+
+    if multiple:
+        func = qtbot.waitSignals
+        arg = [signaller.signal]
+    else:
+        func = qtbot.waitSignal
+        arg = signaller.signal
+
+    if do_timeout:
+        with func(arg, timeout=100):
+            single_shot(signaller.signal, 200)
+        with func(arg, timeout=100):
+            single_shot(signaller.signal, 200)
+    else:
+        with func(arg):
+            signaller.signal.emit()
+        with func(arg):
+            signaller.signal.emit()

pytestqt/plugin.py

@@ -355,6 +355,10 @@ def __init__(self, timeout=1000, raising=False):
         self.timeout = timeout
         self.signal_triggered = False
         self.raising = raising
+        self._timer = QtCore.QTimer()
+        self._timer.setSingleShot(True)
+        if timeout is not None:
+            self._timer.setInterval(timeout)
 
     def wait(self):
         """
@@ -368,12 +372,25 @@ def wait(self):
         if self.timeout is None and not self._signals:
             raise ValueError("No signals or timeout specified.")
         if self.timeout is not None:
-            QtCore.QTimer.singleShot(self.timeout, self._loop.quit)
+            self._timer.timeout.connect(self._quit_loop_by_timeout)
+            self._timer.start()
         self._loop.exec_()
         if not self.signal_triggered and self.raising:
             raise SignalTimeoutError("Didn't get signal after %sms." %
                                       self.timeout)
 
+    def _quit_loop_by_timeout(self):
+        self._loop.quit()
+        self._cleanup()
+
+    def _cleanup(self):
+        if self.timeout is not None:
+            try:
+                self._timer.timeout.disconnect(self._quit_loop_by_timeout)
+            except (TypeError, RuntimeError):
+                # already disconnected by Qt?
+                pass
+
     def __enter__(self):
         return self
 
@@ -426,6 +443,16 @@ def _quit_loop_by_signal(self):
         """
         self.signal_triggered = True
         self._loop.quit()
+        self._cleanup()
+
+    def _cleanup(self):
+        super(SignalBlocker, self)._cleanup()
+        for signal in self._signals:
+            try:
+                signal.disconnect(self._quit_loop_by_signal)
+            except (TypeError, RuntimeError):
+                # already disconnected by Qt?
+                pass
 
 
 class MultiSignalBlocker(_AbstractSignalBlocker):