Lua NAN in terraform

[ashdnazg]

originally reported here: https://springrts.com/mantis/view.php?id=5334 (replay in mantis report)

[f=0017411] Error: LuaRules::RunCallIn: error = 2, AllowCommand, [Internal Lua error: Call failure] [string "LuaRules/Gadgets/unit_terraform.lua"]:306: bad argument 0000003 to 'SetUnitRulesParam' (number expected, got NAN (check your code for div0))
[f=0017412] Error: LuaRules::RunCallIn: error = 2, GameFrame, [Internal Lua error: Call failure] [string "LuaRules/Gadgets/unit_terraform.lua"]:306: bad argument 0000003 to 'SetUnitRulesParam' (number expected, got NAN (check your code for div0))
stack traceback:
    [C]: in function 'SetUnitRulesParam'
    [string "LuaRules/Gadgets/unit_terraform.lua"]:306: in function 'SetTooltip'
    [string "LuaRules/Gadgets/unit_terraform.lua"]:3054: in function 'GameFrame'
    [string "LuaRules/gadgets.lua"]:1008: in function <[string "LuaRules/gadgets.lua"]:1006>
    (tail call): ?

[ashdnazg]

crash/desync is a minor bug? :D

[GoogleFrog]

I have looked through the code and can't see an obvious way for that number to be NaN. Does Spring immediately crash if NaN is used in arithmetic or does the NaN infect many numbers until it eventually crashes at a callout?

[ashdnazg]

The latter There's something setting the height of the ground in at least one spot to NaN which results in propagation to other parts (min/max map height) and eventually it causes an infinite loop in ray tracing

[GoogleFrog]

Are you saying that, in the engine, the height of a location is being set to NaN?

[ashdnazg]

I'm saying that lua is calling an engine function that sets height with NaN as an argument

[GoogleFrog]

Good, that was what I was asking.

[sprunk]

Duplicate of #2361 (actually the other way around but that one has infologs).