recv_match condition adapted to multi vehicle

[noahredon]

The condition now verify the right message received from m.get_srcSystem() instead of that of self.sysid

[peterbarker]

This does feel right to me.

How have you tested this?

My chief concern is that this is a base-class implementation (mavfile.recv_match). Your patches here make recv_match specific to handling mavlink messages, and I don't see anything else in there currently which makes it specific to mavlink messages.

We use the same infrastructure for parsing messages of types other than MAVLink. DFReader is a good example of that, it creates DFMessage objects. In a slightly different world DFReader would only override recv_msg, not recv_match, in which case this patch would kill DFReader (DFMessage objects don't have get_srcSystem.

I can't find an in-tree example of this actually happening, but I think it's a reasonable concern.

At the very least we need a comment / apology to whoever this trips up where we are doing mavlink-message-specific things, and a plea to fix it. More reasonable would be to check the message to see if it has a get_srcSystem() attribute before attempting to use it as a method.

[noahredon]

Sorry for my inactivity, I fixed this problem.