Fix merging networks if one has no feeder.

For some reason this was disallowed and even tested to throw.

src/VariableNetwork.cc

@@ -312,7 +312,7 @@ namespace ChimeraTK {
 
   bool VariableNetwork::merge(VariableNetwork& other) {
     // check if merging is possible
-    if(hasFeedingNode() || !other.hasFeedingNode()) {
+    if(hasFeedingNode() && other.hasFeedingNode()) {
       if((getFeedingNode().getType() == NodeType::ControlSystem &&
              other.getFeedingNode().getType() == NodeType::ControlSystem) ||
           (getFeedingNode().getType() != NodeType::ControlSystem &&

tests/executables_src/testAppModuleConnections.cc

@@ -363,3 +363,34 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(testPseudoArray, T, test_types) {
   app.testModule.consumingPush.read();
   BOOST_CHECK(app.testModule.consumingPush == 33);
 }
+
+/*********************************************************************************************************************/
+/* test case for "merging" two networks */
+
+BOOST_AUTO_TEST_CASE_TEMPLATE(testMergeNetworks, T, test_types) {
+  ChimeraTK::BackendFactory::getInstance().setDMapFilePath("test.dmap");
+
+  TestApplication<T> app;
+  // This creates a first network
+  app.testModule.feedingPush >> app.testModule.consumingPush;
+  // This creates a second network with only consumers
+  app.testModule.consumingPush2 >> app.testModule.consumingPush3;
+  // This merges the two networks
+  app.testModule.consumingPush >> app.testModule.consumingPush2;
+
+
+  // run the app
+  app.initialise();
+  app.run();
+  app.testModule.mainLoopStarted.wait(); // make sure the module's mainLoop() is entered
+
+  // test data transfer
+  app.testModule.feedingPush = 44;
+  app.testModule.feedingPush.write();
+  BOOST_CHECK(app.testModule.consumingPush.readLatest() == true);
+  BOOST_CHECK(app.testModule.consumingPush == 44);
+  BOOST_CHECK(app.testModule.consumingPush2.readLatest() == true);
+  BOOST_CHECK(app.testModule.consumingPush2 == 44);
+  BOOST_CHECK(app.testModule.consumingPush3.readLatest() == true);
+  BOOST_CHECK(app.testModule.consumingPush3 == 44);
+}

tests/executables_src/testIllegalNetworks.cc

@@ -148,24 +148,6 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(testDifferentNrElements, T, test_types) {
   }
 }
 
-/*********************************************************************************************************************/
-/* test case for "merging" two networks */
-
-BOOST_AUTO_TEST_CASE_TEMPLATE(testMergeNetworks, T, test_types) {
-  ChimeraTK::BackendFactory::getInstance().setDMapFilePath("test.dmap");
-
-  TestApplication<T> app;
-  app.testModule.feedingPush >> app.testModule.consumingPush;
-  app.testModule.consumingPush2 >> app.testModule.consumingPush3;
-  try {
-    app.testModule.consumingPush >> app.testModule.consumingPush2;
-    BOOST_ERROR("Exception expected.");
-  }
-  catch(ChimeraTK::logic_error& e) {
-    BOOST_CHECK_NO_THROW(e.what(););
-  }
-}
-
 /*********************************************************************************************************************/
 /* test case for constant as trigger */