MessageFactory::Types returns duplicate message types

[VincidaB]

Environment

• OS Version: Ubuntu 24.04 (docker)
• Source or binary build?
  Harmonic
  And harmonic from source

Description

Multiple identical types sent by MessageFactory::Types()
This issues was found as it breaks gazebo web, and is mentioned on gz-launch issue #246.

Steps to reproduce

1. Install gz-harmonic
2. On a terminal run gz sim -v 4 -s -r shapes.sdf
3. In another terminal run gz launch -v 4 /usr/share/gz/gz-launch7/configs/websocket.gzlaunch
4. Go to web app and click connect

Output

In the browser's console we get

ERROR Error: duplicate name 'Any' in Namespace .gz.msgs

cf the aforementioned gz-launch issue where the op posted logs.

I was able to fix the problem on the gz-launch side of things but my fix isn't great for many reasons.

gz-msgs/core/src/MessageFactory.cc

Lines 129 to 142 in eaf96af

	void MessageFactory::Types(std::vector<std::string> &_types)
	{
	_types.clear();
	// Return the list of all known message types.
	std::map<std::string, FactoryFn>::const_iterator iter;
	for (iter = msgMap.begin(); iter != msgMap.end(); ++iter)
	{
	_types.push_back(iter->first);
	}
	// Add the types loaded from descriptor files
	this->dynamicFactory->Types(_types);
	}

I am not familiar yet with all of gazebo's components, and not at all with gz-msgs, but the above piece of code might be responsible for adding additional messages on the line :

gz-msgs/core/src/MessageFactory.cc

Line 141 in eaf96af

this->dynamicFactory->Types(_types);

The messages that are part of msgMap have no duplicate of course, but after wrench, we get an additional message of type Any.