diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index 2d09ffa60565..cb3bd0769856 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -1148,6 +1148,18 @@ public String toDefaultValueWithParam(String name, Schema schema) {
      **/
     @SuppressWarnings("static-method")
     public String getSchemaType(Schema schema) {
+        // TODO better logic to handle compose schema
+        if (schema instanceof ComposedSchema) { // composed schema
+            ComposedSchema cs = (ComposedSchema) schema;
+            for (Schema s : cs.getAllOf()) {
+                if (s != null) {
+                    // using the first schema defined in allOf
+                    schema = s;
+                    break;
+                }
+            }
+        }
+
         if (StringUtils.isNotBlank(schema.get$ref())) { // object
             // get the schema/model name from $ref
             String schemaName = ModelUtils.getSimpleRef(schema.get$ref());
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5ClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5ClientCodegen.java
index 27678ade427c..9f379cd8f797 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5ClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppQt5ClientCodegen.java
@@ -345,6 +345,7 @@ public String toDefaultValue(Schema p) {
     @Override
     public String getSchemaType(Schema p) {
         String openAPIType = super.getSchemaType(p);
+
         String type = null;
         if (typeMapping.containsKey(openAPIType)) {
             type = typeMapping.get(openAPIType);
@@ -362,6 +363,11 @@ public String getSchemaType(Schema p) {
 
     @Override
     public String toModelName(String type) {
+        if (type == null) {
+            LOGGER.warn("Model name can't be null. Defaul to 'UnknownModel'.");
+            type = "UnknownModel";
+        }
+
         if (typeMapping.keySet().contains(type) ||
                 typeMapping.values().contains(type) ||
                 importMapping.values().contains(type) ||
diff --git a/samples/client/petstore/qt5cpp/client/SWGPetApi.cpp b/samples/client/petstore/qt5cpp/client/SWGPetApi.cpp
index fea2b44e2447..666ce2c63233 100644
--- a/samples/client/petstore/qt5cpp/client/SWGPetApi.cpp
+++ b/samples/client/petstore/qt5cpp/client/SWGPetApi.cpp
@@ -30,7 +30,7 @@ SWGPetApi::SWGPetApi(QString host, QString basePath) {
 }
 
 void
-SWGPetApi::addPet(SWGPet& swg_pet) {
+SWGPetApi::addPet(std::shared_ptr<SWGSWGPet>& swg_pet) {
     QString fullPath;
     fullPath.append(this->host).append(this->basePath).append("/pet");
 
@@ -141,13 +141,47 @@ SWGPetApi::findPetsByStatus(QList<QString*>* status) {
     fullPath.append(this->host).append(this->basePath).append("/pet/findByStatus");
 
 
-    if (fullPath.indexOf("?") > 0)
-      fullPath.append("&");
-    else
-      fullPath.append("?");
-    fullPath.append(QUrl::toPercentEncoding("status"))
-        .append("=")
-        .append(QUrl::toPercentEncoding(stringValue(status)));
+
+
+    if (status->size() > 0) {
+      if (QString("csv").indexOf("multi") == 0) {
+        foreach(QString* t, *status) {
+          if (fullPath.indexOf("?") > 0)
+            fullPath.append("&");
+          else
+            fullPath.append("?");
+          fullPath.append("status=").append(stringValue(t));
+        }
+      }
+      else if (QString("csv").indexOf("ssv") == 0) {
+        if (fullPath.indexOf("?") > 0)
+          fullPath.append("&");
+        else
+          fullPath.append("?");
+        fullPath.append("status=");
+        qint32 count = 0;
+        foreach(QString* t, *status) {
+          if (count > 0) {
+            fullPath.append(" ");
+          }
+          fullPath.append(stringValue(t));
+        }
+      }
+      else if (QString("csv").indexOf("tsv") == 0) {
+        if (fullPath.indexOf("?") > 0)
+          fullPath.append("&");
+        else
+          fullPath.append("?");
+        fullPath.append("status=");
+        qint32 count = 0;
+        foreach(QString* t, *status) {
+          if (count > 0) {
+            fullPath.append("\t");
+          }
+          fullPath.append(stringValue(t));
+        }
+      }
+    }
 
 
     SWGHttpRequestWorker *worker = new SWGHttpRequestWorker();
@@ -214,13 +248,47 @@ SWGPetApi::findPetsByTags(QList<QString*>* tags) {
     fullPath.append(this->host).append(this->basePath).append("/pet/findByTags");
 
 
-    if (fullPath.indexOf("?") > 0)
-      fullPath.append("&");
-    else
-      fullPath.append("?");
-    fullPath.append(QUrl::toPercentEncoding("tags"))
-        .append("=")
-        .append(QUrl::toPercentEncoding(stringValue(tags)));
+
+
+    if (tags->size() > 0) {
+      if (QString("csv").indexOf("multi") == 0) {
+        foreach(QString* t, *tags) {
+          if (fullPath.indexOf("?") > 0)
+            fullPath.append("&");
+          else
+            fullPath.append("?");
+          fullPath.append("tags=").append(stringValue(t));
+        }
+      }
+      else if (QString("csv").indexOf("ssv") == 0) {
+        if (fullPath.indexOf("?") > 0)
+          fullPath.append("&");
+        else
+          fullPath.append("?");
+        fullPath.append("tags=");
+        qint32 count = 0;
+        foreach(QString* t, *tags) {
+          if (count > 0) {
+            fullPath.append(" ");
+          }
+          fullPath.append(stringValue(t));
+        }
+      }
+      else if (QString("csv").indexOf("tsv") == 0) {
+        if (fullPath.indexOf("?") > 0)
+          fullPath.append("&");
+        else
+          fullPath.append("?");
+        fullPath.append("tags=");
+        qint32 count = 0;
+        foreach(QString* t, *tags) {
+          if (count > 0) {
+            fullPath.append("\t");
+          }
+          fullPath.append(stringValue(t));
+        }
+      }
+    }
 
 
     SWGHttpRequestWorker *worker = new SWGHttpRequestWorker();
@@ -337,7 +405,7 @@ SWGPetApi::getPetByIdCallback(SWGHttpRequestWorker * worker) {
 }
 
 void
-SWGPetApi::updatePet(SWGPet& swg_pet) {
+SWGPetApi::updatePet(std::shared_ptr<SWGSWGPet>& swg_pet) {
     QString fullPath;
     fullPath.append(this->host).append(this->basePath).append("/pet");
 
diff --git a/samples/client/petstore/qt5cpp/client/SWGPetApi.h b/samples/client/petstore/qt5cpp/client/SWGPetApi.h
index 70ce602c51cb..5f040d8a32a1 100644
--- a/samples/client/petstore/qt5cpp/client/SWGPetApi.h
+++ b/samples/client/petstore/qt5cpp/client/SWGPetApi.h
@@ -36,12 +36,12 @@ class SWGPetApi: public QObject {
     QString basePath;
     QMap<QString, QString> defaultHeaders;
 
-    void addPet(SWGPet& swg_pet);
+    void addPet(std::shared_ptr<SWGSWGPet>& swg_pet);
     void deletePet(qint64 pet_id, QString* api_key);
     void findPetsByStatus(QList<QString*>* status);
     void findPetsByTags(QList<QString*>* tags);
     void getPetById(qint64 pet_id);
-    void updatePet(SWGPet& swg_pet);
+    void updatePet(std::shared_ptr<SWGSWGPet>& swg_pet);
     void updatePetWithForm(qint64 pet_id, QString* name, QString* status);
     void uploadFile(qint64 pet_id, QString* additional_metadata, SWGHttpRequestInputFileElement* file);
     
diff --git a/samples/client/petstore/qt5cpp/client/SWGStoreApi.cpp b/samples/client/petstore/qt5cpp/client/SWGStoreApi.cpp
index b04e57e273b0..d61f26ba9fb5 100644
--- a/samples/client/petstore/qt5cpp/client/SWGStoreApi.cpp
+++ b/samples/client/petstore/qt5cpp/client/SWGStoreApi.cpp
@@ -196,7 +196,7 @@ SWGStoreApi::getOrderByIdCallback(SWGHttpRequestWorker * worker) {
 }
 
 void
-SWGStoreApi::placeOrder(SWGOrder& swg_order) {
+SWGStoreApi::placeOrder(std::shared_ptr<SWGSWGOrder>& swg_order) {
     QString fullPath;
     fullPath.append(this->host).append(this->basePath).append("/store/order");
 
diff --git a/samples/client/petstore/qt5cpp/client/SWGStoreApi.h b/samples/client/petstore/qt5cpp/client/SWGStoreApi.h
index 321a0e609280..bfa20043c5c3 100644
--- a/samples/client/petstore/qt5cpp/client/SWGStoreApi.h
+++ b/samples/client/petstore/qt5cpp/client/SWGStoreApi.h
@@ -38,7 +38,7 @@ class SWGStoreApi: public QObject {
     void deleteOrder(QString* order_id);
     void getInventory();
     void getOrderById(qint64 order_id);
-    void placeOrder(SWGOrder& swg_order);
+    void placeOrder(std::shared_ptr<SWGSWGOrder>& swg_order);
     
 private:
     void deleteOrderCallback (SWGHttpRequestWorker * worker);
diff --git a/samples/client/petstore/qt5cpp/client/SWGUserApi.cpp b/samples/client/petstore/qt5cpp/client/SWGUserApi.cpp
index bb02a3d5de61..f79093e1cd95 100644
--- a/samples/client/petstore/qt5cpp/client/SWGUserApi.cpp
+++ b/samples/client/petstore/qt5cpp/client/SWGUserApi.cpp
@@ -30,7 +30,7 @@ SWGUserApi::SWGUserApi(QString host, QString basePath) {
 }
 
 void
-SWGUserApi::createUser(SWGUser& swg_user) {
+SWGUserApi::createUser(std::shared_ptr<SWGSWGUser>& swg_user) {
     QString fullPath;
     fullPath.append(this->host).append(this->basePath).append("/user");
 
@@ -418,7 +418,7 @@ SWGUserApi::logoutUserCallback(SWGHttpRequestWorker * worker) {
 }
 
 void
-SWGUserApi::updateUser(QString* username, SWGUser& swg_user) {
+SWGUserApi::updateUser(QString* username, std::shared_ptr<SWGSWGUser>& swg_user) {
     QString fullPath;
     fullPath.append(this->host).append(this->basePath).append("/user/{username}");
 
diff --git a/samples/client/petstore/qt5cpp/client/SWGUserApi.h b/samples/client/petstore/qt5cpp/client/SWGUserApi.h
index e6ad3c2e0926..816bd10ab95a 100644
--- a/samples/client/petstore/qt5cpp/client/SWGUserApi.h
+++ b/samples/client/petstore/qt5cpp/client/SWGUserApi.h
@@ -15,6 +15,7 @@
 
 #include "SWGHttpRequest.h"
 
+#include <QList>
 #include <QString>
 #include "SWGUser.h"
 
@@ -34,14 +35,14 @@ class SWGUserApi: public QObject {
     QString basePath;
     QMap<QString, QString> defaultHeaders;
 
-    void createUser(SWGUser& swg_user);
+    void createUser(std::shared_ptr<SWGSWGUser>& swg_user);
     void createUsersWithArrayInput(QList<SWGUser*>*& swg_user);
     void createUsersWithListInput(QList<SWGUser*>*& swg_user);
     void deleteUser(QString* username);
     void getUserByName(QString* username);
     void loginUser(QString* username, QString* password);
     void logoutUser();
-    void updateUser(QString* username, SWGUser& swg_user);
+    void updateUser(QString* username, std::shared_ptr<SWGSWGUser>& swg_user);
     
 private:
     void createUserCallback (SWGHttpRequestWorker * worker);