If you set the "particle_buffer_size" property of a "stream" prototype to 1, the particle will not be displayed properly.
Setting it to 2 does not have display error, but it creates at least 2 particles for each shot, regardless of the values of "particle_spawn_interval" and "particle_spawn_timeout"
This bug is not likely to happen in vanilla games, so it is fine if you fix it for 0.15.
Steps to reproduce:
1a) Change the "particle_buffer_size" of "flamethrower-fire-stream" to 1.
1b) start a game and observe when any flamethrower turret fires.
It will be like this:
Image
2a) Now change the value of "particle_buffer_size" to 2, "particle_spawn_interval" to 60 and "particle_spawn_timeout" to 1.2b) Also give flamethrower turrets a very long cooldown.
2c) Observe. (May need to turn on debug info to see the problem.)
Alternatively
You can download this mod: It has carried out step 1 for flamethrower turret, and step 2 for the handheld flamethrower gun.
Plus, it has also changed the actions of the flame particles so they now create smoke entities on hit, triggering messages to be printed.
"smoke" = flamethrower turret
"smoke-fast" = handheld flamethrower
Also load this save for quick start: It is specifically made for this bug report, no other mod is needed.
(Creative Mode was used to create the entities, but it is not needed anymore.)
Image
As you can see, 2 messages "smoke-fast" are printed for each shot from handheld flamethrower.I use stream to make bullets without the need of collision box, so walls will not block their path.