Bonnet open warning?

[Mark604]

K9 Petrol -
A bit complicated but I had a warning light spanner come on today. I'd stopped at a garage just before home, switched off, opened the bonnet, filled the washer bottle, shut the bonnet, started the car and the spanner came on with a message saying engine fault.
I switched off, thought for a minute, switched on and the warning lights were off.
As I was a hundred metres or so from home I drove back, but halfway there they came on again and the engine seemed as though it was missing a cylinder - i.e. no power and lumpy.

I coasted into my driveway and switched off.
Walked round the front of the car and the bonnet was unlatched - I'd obviously not closed it properly.
Closed it and switched the engine on - but no warning lights on again and now I'm reluctant to go out in it.
Yes, I'll probably call the garage tomorrow but for now - and I can't see this in the handbook - what warnings would come on if the bonnet was open/unlatched? Surely not what I had and it was just a coincidence? But is there a warning light or something for the bonnet?

I see the warnings for the doors and boot, but not bonnet.

[Mark604]

Just to update this - it seems I was getting a misfire from a faulty spark plug. All sorted under warranty.