Fix clear-smoke memory leaks

[Crystalwarrior]

Delete the instances of smoke that are already erased from the flows vectors

thanks @Bumber64 for the help!

[Crystalwarrior]

Could potentially expand this script to be general-purpose clear-flows at a later date

[myk002]

why can't this be deleted inline? other tools successfully do it that way, e.g. https://github.com/DFHack/dfhack/blob/develop/plugins/lua/dwarfvet.lua#L129-L137

[Bumber64]

Given Discord discussion, the script should now be something like this:

function removeFlow(flow) --have DF remove the flow
    if not flow then
        return
    end
    flow.flags.DEAD = true

    local block = dfhack.maps.getTileBlock(flow.pos)
    if block then
        block.flow_pool.flags.active = true
    else
        df.global.world.orphaned_flow_pool.flags.active = true
    end
end

function removeFlows(flow_type) --remove all if flow_type is nil
    local count = 0
    for _,flow in ipairs(df.global.flows) do
        if not flow.flags.DEAD and (flow_type == nil or flow.type == flow_type) then
            removeFlow(flow)
            count = count + 1
        end
    end

    return count
end

function clearSmoke()
    if dfhack.isWorldLoaded() then
        print(('%d smoke flows removed.'):format(removeFlows(df.flow_type.Smoke)))
    else
        qerror('World not loaded!')
    end
end

clearSmoke()

I think we could probably turn this into a @module to allow the removeFlow functions to be reused elsewhere. Otherwise, we could just implement those in Maps and add them to the Lua API.

[Bumber64]

Should be

if not dfhack_flags.module then
    clearSmoke()
end

so it doesn't run when used as a module.

Also, there's an issue with your end of file. Post a comment on this PR that says pre-commit.ci autofix to fix it.

[myk002]

pre-commit.ci autofix