tdf#68016 Write fixture for current behaviour of SfxListener

Also: Make destructor of SfxListener more robust, so that it can be used
in tests.

Change-Id: I02b273ca8e527705c2d3ea3295ed0dec1c4f83ae
Reviewed-on: https://gerrit.libreoffice.org/16483Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

svl/qa/unit/notify/test_SfxBroadcaster.cxx

@@ -22,12 +22,16 @@ class SfxBroadcasterTest : public CppUnit::TestFixture
     void AddingListenersIncreasesCount();
     void RemovingListenersDecreasesCount();
     void HintsAreNotForwardedToRemovedListeners();
+    void SameListenerCanBeAddedMoreThanOnce();
+    void StoppingListeningAffectsOnlyFirstOfIdenticalListeners();
 
     // Adds code needed to register the test suite
     CPPUNIT_TEST_SUITE(SfxBroadcasterTest);
     CPPUNIT_TEST(AddingListenersIncreasesCount);
     CPPUNIT_TEST(RemovingListenersDecreasesCount);
     CPPUNIT_TEST(HintsAreNotForwardedToRemovedListeners);
+    CPPUNIT_TEST(SameListenerCanBeAddedMoreThanOnce);
+    CPPUNIT_TEST(StoppingListeningAffectsOnlyFirstOfIdenticalListeners);
 
     CPPUNIT_TEST_SUITE_END();
 };
@@ -93,6 +97,27 @@ SfxBroadcasterTest::HintsAreNotForwardedToRemovedListeners()
     CPPUNIT_ASSERT_EQUAL(false, sl1.NotifyWasCalled());
 }
 
+void
+SfxBroadcasterTest::SameListenerCanBeAddedMoreThanOnce()
+{
+    MockedSfxListener sl;
+    SfxBroadcaster sb;
+    sb.AddListener(sl);
+    sb.AddListener(sl);
+    CPPUNIT_ASSERT_EQUAL((size_t)2, sb.GetListenerCount());
+}
+
+void
+SfxBroadcasterTest::StoppingListeningAffectsOnlyFirstOfIdenticalListeners()
+{
+    MockedSfxListener sl;
+    SfxBroadcaster sb;
+    sb.AddListener(sl);
+    sb.AddListener(sl);
+    sb.RemoveListener(sl);
+    CPPUNIT_ASSERT_EQUAL((size_t)1, sb.GetListenerCount());
+}
+
 CPPUNIT_TEST_SUITE_REGISTRATION(SfxBroadcasterTest);
 
 CPPUNIT_PLUGIN_IMPLEMENT();

svl/source/notify/lstner.cxx

@@ -68,7 +68,10 @@ SfxListener::~SfxListener()
 
 void SfxListener::RemoveBroadcaster_Impl( SfxBroadcaster& rBroadcaster )
 {
-    mpImpl->maBCs.erase( std::find( mpImpl->maBCs.begin(), mpImpl->maBCs.end(), &rBroadcaster ) );
+    auto it = std::find( mpImpl->maBCs.begin(), mpImpl->maBCs.end(), &rBroadcaster );
+    if (it != mpImpl->maBCs.end()) {
+        mpImpl->maBCs.erase( it );
+    }
 }