* Added asserts when building a HeaderList and removed checks for handle

validity.
* Removed explicit move semantic when cloning a MessageBuilder.
* Renamed clone() to try_clone() in ClonablePtr class.

include/cppkafka/clonable_ptr.h

@@ -60,7 +60,7 @@ public:
      * \param rhs The pointer to be copied
      */
     ClonablePtr(const ClonablePtr& rhs)
-    : handle_(std::unique_ptr<T, Deleter>(rhs.clone(), rhs.get_deleter())),
+    : handle_(std::unique_ptr<T, Deleter>(rhs.try_clone(), rhs.get_deleter())),
       cloner_(rhs.get_cloner()) {
 
     }
@@ -72,7 +72,7 @@ public:
      */
     ClonablePtr& operator=(const ClonablePtr& rhs) {
         if (this != &rhs) {
-            handle_ = std::unique_ptr<T, Deleter>(rhs.clone(), rhs.get_deleter());
+            handle_ = std::unique_ptr<T, Deleter>(rhs.try_clone(), rhs.get_deleter());
             cloner_ = rhs.get_cloner();
         }
         return *this;
@@ -124,10 +124,7 @@ public:
         return static_cast<bool>(handle_);
     }
 private:
-    /**
-     * \brief Clones the internal pointer using the specified cloner function.
-     */
-    T* clone() const {
+    T* try_clone() const {
         return cloner_ ? cloner_(get()) : get();
     }
     

include/cppkafka/header_list.h

@@ -192,7 +192,7 @@ bool operator!=(const HeaderList<HeaderType>& lhs, const HeaderList<HeaderType>
 
 template <typename HeaderType>
 HeaderList<HeaderType> HeaderList<HeaderType>::make_non_owning(rd_kafka_headers_t* handle) {
-    return handle ? HeaderList(handle, NonOwningTag()) : HeaderList();
+    return HeaderList(handle, NonOwningTag());
 }
 
 template <typename HeaderType>
@@ -204,21 +204,19 @@ HeaderList<HeaderType>::HeaderList()
 template <typename HeaderType>
 HeaderList<HeaderType>::HeaderList(size_t reserve)
 : handle_(rd_kafka_headers_new(reserve), &rd_kafka_headers_destroy, &rd_kafka_headers_copy) {
-
+    assert(reserve);
 }
 
 template <typename HeaderType>
 HeaderList<HeaderType>::HeaderList(rd_kafka_headers_t* handle)
-: handle_(handle,
-          handle ? &rd_kafka_headers_destroy : nullptr,
-          handle ? &rd_kafka_headers_copy : nullptr) { //if we own the header list, we clone it on copy
+: handle_(handle, &rd_kafka_headers_destroy, &rd_kafka_headers_copy) { //if we own the header list, we clone it on copy
+    assert(handle);
 }
 
 template <typename HeaderType>
 HeaderList<HeaderType>::HeaderList(rd_kafka_headers_t* handle, NonOwningTag)
-: handle_(handle,
-          handle ? &dummy_deleter : nullptr,
-          nullptr) { //if we don't own the header list, we forward the handle on copy.
+: handle_(handle, &dummy_deleter, nullptr) { //if we don't own the header list, we forward the handle on copy.
+    assert(handle);
 }
 
 // Methods

include/cppkafka/message.h

@@ -133,6 +133,9 @@ public:
      */
     void set_header_list(const HeaderListType& headers) {
         assert(handle_);
+        if (!headers) {
+            return; //nothing to set
+        }
         rd_kafka_headers_t* handle_copy = rd_kafka_headers_copy(headers.get_handle());
         rd_kafka_message_set_headers(handle_.get(), handle_copy);
         header_list_ = HeaderListType::make_non_owning(handle_copy);

include/cppkafka/message_builder.h

@@ -245,8 +245,7 @@ BasicMessageBuilder<T, C>::BasicMessageBuilder(const Message& message)
   key_(Buffer(message.get_key().get_data(), message.get_key().get_size())),
 #if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
   header_list_(message.get_header_list() ?
-               rd_kafka_headers_copy(message.get_header_list().get_handle()) :
-               nullptr), //copy and assume ownership
+               rd_kafka_headers_copy(message.get_header_list().get_handle()) : nullptr), //copy headers
 #endif
   payload_(Buffer(message.get_payload().get_data(), message.get_payload().get_size())),
   timestamp_(message.get_timestamp() ? message.get_timestamp().get().get_timestamp() :
@@ -263,8 +262,7 @@ BasicMessageBuilder<T, C>::BasicMessageBuilder(const BasicMessageBuilder<U, V>&
   partition_(rhs.partition()),
 #if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
   header_list_(rhs.header_list() ?
-               rd_kafka_headers_copy(rhs.header_list().get_handle()) :
-               nullptr), //copy headers
+               rd_kafka_headers_copy(rhs.header_list().get_handle()) : nullptr), //copy headers
 #endif
   timestamp_(rhs.timestamp()),
   user_data_(rhs.user_data()),
@@ -279,7 +277,8 @@ BasicMessageBuilder<T, C>::BasicMessageBuilder(BasicMessageBuilder<U, V>&& rhs)
 : topic_(rhs.topic()),
   partition_(rhs.partition()),
 #if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
-  header_list_(rhs.header_list().release_handle()), //assume ownership
+  header_list_(rhs.header_list() ?
+               rhs.header_list().release_handle() : nullptr), //assume header ownership
 #endif
   timestamp_(rhs.timestamp()),
   user_data_(rhs.user_data()),
@@ -476,15 +475,16 @@ public:
     
 
     MessageBuilder clone() const {
-        return std::move(MessageBuilder(topic()).
-            key(Buffer(key().get_data(), key().get_size())).
+        MessageBuilder builder(topic());
+        builder.key(Buffer(key().get_data(), key().get_size())).
 #if (RD_KAFKA_VERSION >= RD_KAFKA_HEADERS_SUPPORT_VERSION)
             headers(header_list()).
 #endif
             payload(Buffer(payload().get_data(), payload().get_size())).
             timestamp(timestamp()).
             user_data(user_data()).
-            internal(internal()));
+            internal(internal());
+        return builder;
     }
 };
 

src/producer.cpp

@@ -70,7 +70,7 @@ void Producer::produce(const MessageBuilder& builder) {
 }
 
 void Producer::produce(MessageBuilder&& builder) {
-    do_produce(builder, MessageBuilder::HeaderListType(builder.header_list().release_handle())); //move headers
+    do_produce(builder, std::move(builder.header_list())); //move headers
 }
 
 void Producer::produce(const Message& message) {