Description of problem:

This is related to systemd BZ #2158724.

When a DBus client sends a non-UTF8 message through the bus, DBus disconnects the client without logging anything, we makes it hard to understand the reason for disconnection.
In my case, I was troubleshooting for BZ #2158724, I could see with strace that the systemd connection was getting disconnected after dbus read some messages.
To find out this was due to a message corruption detection (done by validate_body_helper() function), I had to set up a breakpoint within gdb in various failure locations, which is definitely not user-friendly.
If DBus was reporting where the corruption is and for which connection, this would have helped speed up the troubleshooting

Version-Release number of selected component (if applicable):

dbus-1.12.8-x

How reproducible:

Send a non-UTF8 message through the bus, didn't build any reproducer for that.