Use macro instead of checking if string is empty manually...

src/c-wrapper/api/c-chat-message.cpp

@@ -90,13 +90,13 @@ LinphoneChatMessageCbs *linphone_chat_message_get_callbacks(const LinphoneChatMe
 // =============================================================================
 
 LinphoneChatRoom *linphone_chat_message_get_chat_room(const LinphoneChatMessage *msg) {
-	return L_GET_C_BACK_PTR(L_GET_CPP_PTR_FROM_C_OBJECT(msg)->getChatRoom());
+	shared_ptr<const LinphonePrivate::ChatMessage> message = L_GET_CPP_PTR_FROM_C_OBJECT(msg);
+	shared_ptr<LinphonePrivate::ChatRoom> room = message->getChatRoom();
+	return L_GET_C_BACK_PTR(room);
 }
 
 const char *linphone_chat_message_get_external_body_url(const LinphoneChatMessage *msg) {
-	const string& external_body_url = L_GET_CPP_PTR_FROM_C_OBJECT(msg)->getExternalBodyUrl();
-	if (external_body_url.empty()) return NULL;
-	return external_body_url.c_str();
+	return L_STRING_TO_C(L_GET_CPP_PTR_FROM_C_OBJECT(msg)->getExternalBodyUrl());
 }
 
 void linphone_chat_message_set_external_body_url(LinphoneChatMessage *msg, const char *url) {
@@ -164,9 +164,7 @@ bool_t linphone_chat_message_is_read(LinphoneChatMessage *msg) {
 }
 
 const char *linphone_chat_message_get_appdata(const LinphoneChatMessage *msg) {
-	const string& appData = L_GET_CPP_PTR_FROM_C_OBJECT(msg)->getAppdata();
-	if (appData.empty()) return NULL;
-	return appData.c_str();
+	return L_STRING_TO_C(L_GET_CPP_PTR_FROM_C_OBJECT(msg)->getAppdata());
 }
 
 void linphone_chat_message_set_appdata(LinphoneChatMessage *msg, const char *data) {
@@ -196,9 +194,7 @@ const LinphoneAddress *linphone_chat_message_get_to_address(LinphoneChatMessage
 }
 
 const char *linphone_chat_message_get_file_transfer_filepath(LinphoneChatMessage *msg) {
-	const string& path = L_GET_CPP_PTR_FROM_C_OBJECT(msg)->getFileTransferFilepath();
-	if (path.empty()) return NULL;
-	return path.c_str();
+	return L_STRING_TO_C(L_GET_CPP_PTR_FROM_C_OBJECT(msg)->getFileTransferFilepath());
 }
 
 void linphone_chat_message_set_file_transfer_filepath(LinphoneChatMessage *msg, const char *filepath) {
@@ -247,9 +243,7 @@ void linphone_chat_message_remove_custom_header(LinphoneChatMessage *msg, const
 }
 
 const char *linphone_chat_message_get_custom_header(LinphoneChatMessage *msg, const char *header_name) {
-	const string& header = L_GET_PRIVATE_FROM_C_OBJECT(msg)->getSalCustomHeaderValue(header_name);
-	if (header.empty()) return NULL;
-	return header.c_str();
+	return L_STRING_TO_C(L_GET_PRIVATE_FROM_C_OBJECT(msg)->getSalCustomHeaderValue(header_name));
 }
 
 const LinphoneErrorInfo *linphone_chat_message_get_error_info(const LinphoneChatMessage *msg) {
@@ -329,9 +323,7 @@ void * linphone_chat_message_get_message_state_changed_cb_user_data(LinphoneChat
 // =============================================================================
 
 const char * linphone_chat_message_get_content_type(const LinphoneChatMessage *msg) {
-	const string& contentType = L_GET_PRIVATE_FROM_C_OBJECT(msg)->getContentType();
-	if (contentType.empty()) return NULL;
-	return contentType.c_str();
+	return L_STRING_TO_C(L_GET_PRIVATE_FROM_C_OBJECT(msg)->getContentType());
 }
 
 void linphone_chat_message_set_content_type(LinphoneChatMessage *msg, const char *content_type) {
@@ -339,9 +331,7 @@ void linphone_chat_message_set_content_type(LinphoneChatMessage *msg, const char
 }
 
 const char *linphone_chat_message_get_text(const LinphoneChatMessage *msg) {
-	const string& text = L_GET_PRIVATE_FROM_C_OBJECT(msg)->getText();
-	if (text.empty()) return NULL;
-	return text.c_str();
+	return L_STRING_TO_C(L_GET_PRIVATE_FROM_C_OBJECT(msg)->getText());
 }
 
 int linphone_chat_message_set_text(LinphoneChatMessage *msg, const char* text) {