The bug
When you shoot a flaming arrow at a waterlogged campfire, you can light even though it is waterlogged.
MC-151365
Flaming arrows can light waterlogged campfires
Resolved
Fixed
6
Confirmed
(Unassigned)
Minecraft 1.14.1 Pre-Release 2, Minecraft 1.14.1
Minecraft 1.14.2 Pre-Release 1
Retrieved
Not very related but campfires can't be lit by projectiles that are shot by mobs when on servers.