Check if valid msg before dispatch

Author: Mauro Passerino

rclcpp/include/rclcpp/any_subscription_callback.hpp

@@ -185,6 +185,12 @@ class AnySubscriptionCallback
     ConstMessageSharedPtr message, const rclcpp::MessageInfo & message_info)
   {
     TRACEPOINT(callback_start, static_cast<const void *>(this), true);
+
+    // If the message is not valid, return.
+    if(!message) {
+      return;
+    }
+
     if (const_shared_ptr_callback_) {
       const_shared_ptr_callback_(message);
     } else if (const_shared_ptr_with_info_callback_) {
@@ -208,6 +214,12 @@ class AnySubscriptionCallback
     MessageUniquePtr message, const rclcpp::MessageInfo & message_info)
   {
     TRACEPOINT(callback_start, static_cast<const void *>(this), true);
+
+    // If the message is not valid, return.
+    if(!message) {
+      return;
+    }
+
     if (shared_ptr_callback_) {
       typename std::shared_ptr<MessageT> shared_message = std::move(message);
       shared_ptr_callback_(shared_message);

rclcpp/include/rclcpp/experimental/subscription_intra_process.hpp

@@ -129,14 +129,8 @@ class SubscriptionIntraProcess : public SubscriptionIntraProcessBase
 
     if (any_callback_.use_take_shared_method()) {
       shared_msg = buffer_->consume_shared();
-      if(!shared_msg) {
-        return nullptr;
-      }
     } else {
       unique_msg = buffer_->consume_unique();
-      if(!unique_msg) {
-        return nullptr;
-      }
     }
     return std::static_pointer_cast<void>(
       std::make_shared<std::pair<ConstMessageSharedPtr, MessageUniquePtr>>(