VehicleSetFix — 42.17 Compatibility Patch
VehicleSetFix — 42.17 Compatibility Patch
⚠ Deprecation Notice
This mod no longer provides a reliable fix and [b]should be removed from your mod list[/b].
The two approaches that could intercept [i]getVehicles():get(i)[/i] transparently both turned out to be incompatible with the game:
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[*] [b]Patching IsoCell at the class level[/b] — not possible because [i]IsoCell[/i] is not registered as a Lua-accessible table in 42.17.
[*] [b]Wrapping the [i]getCell()[/i] global[/b] — breaks vanilla map interaction. Any i that passes [i]getCell()[/i] as an argument to a Java constructor (building furniture, placing objects, constructing traps, etc.) receives a Lua proxy table instead of the expected [i]IsoCell[/i] object, causing actions to consume materials without placing anything.
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The only remaining approach — patching individual mod methods case by case — is not a sustainable solution and does not cover mods whose affected functions are defined as locals.
[b]The correct fix is for each affected mod to update its iteration pattern from [i]get(i)[/i] to [i]iterator()[/i].[/b] If a mod in your list is still crashing with [i]"Object tried to call nil"[/i] on a [i]getVehicles()[/i] call, contact the mod author and link them to this page.
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[b]Fixes vehicle mod crashes introduced by the 42.17 update.[/b]
The Problem
In version [b]42.17[/b], Project Zomboid changed the internal return type of [i]IsoCell.getVehicles()[/i] from [i]ArrayList[/i] to [i]Set[/i]. This silently breaks any mod written for 42.16 that iterates vehicles using the [i]vehicles:get(i)[/i] pattern, since [i]Set[/i] has no such method.
The result is an [i]"Object tried to call nil"[/i] crash when interacting with vehicles — opening the radial menu, refueling, etc.
What This Mod Does
Intercepts [i]getVehicles()[/i] calls and returns a proxy that adds [i]get(index)[/i] support, without breaking mods already updated for 42.17 that use [i]iterator()[/i].
No files from other mods are modified.
How It Works
The mod attempts three strategies in order, stopping at the first that succeeds.
[b]Strategy 1 — IsoCell class table patch[/b]
Overrides [i]IsoCell.getVehicles[/i] at the class level. Every call to [i]getVehicles()[/i] from any mod, regardless of how the cell was obtained, returns the proxy. This is the safest and most complete approach. The console will log [i]Strategy 1: patched IsoCell.getVehicles[/i] if successful.
[b]Strategy 2 — getCell() global override[/b]
Falls back to wrapping the [i]getCell()[/i] Lua global if the class table is not accessible. Covers mods that call [i]getCell():getVehicles()[/i] directly (e.g. RV Interior server-side). Does [b]not[/b] cover calls made via [i]playerObj:getCell():getVehicles()[/i].
[b]Strategy 3 — FindVehicleGas replacement[/b]
If strategies 1 and 2 are insufficient, replaces the [i]FindVehicleGas[/i] global defined by PZK Car Pack with an iterator-based equivalent. Functionally identical to the original.
Impact on Correctly Updated Mods
Mods already written for 42.17 that use [i]iterator()[/i] are [b]not affected[/b].
The proxy returned by the patched [i]getVehicles()[/i] forwards all unknown method calls to the underlying Java Set via [i]__index[/i], so [i]size()[/i], [i]iterator()[/i], [i]isEmpty()[/i], [i]contains()[/i] and any other Set method continue to work normally.
The one exception is [i]pairs(vehicleList)[/i] — Lua 5.1 has no [i]__pairs[/i] metamethod, so iterating the proxy with [i]pairs()[/i] will not yield vehicles. However, [i]pairs()[/i] was never a correct way to iterate a Java collection and no well-written 42.17 mod should rely on it.
Known Fixed Mods
[list]
[*] [b]PZK Vanilla Plus Car Pack[/b] — crash in [i]FindVehicleGas[/i] when opening the vehicle menu
[*] [b]PROJECT RV Interior[/b] — crash on saves migrated from 42.16
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Other mods affected by the same change are also covered automatically.
Compatibility
[list]
[*] Requires [b]42.17+[/b]. On 42.16 the mod detects the original ArrayList and does nothing.
[*] Compatible with multiplayer (client and server).
[*] Should be loaded [b]before[/b] the mods it fixes in the load order.
[*] Does not affect existing saves.
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For Mod Authors
If your mod iterates vehicles and broke in 42.17, the correct pattern is now:
local it = cell:getVehicles():iterator()
while it:hasNext() do
local vehicle = it:next()
-- ...
end
This mod is a temporary compatibility shim while affected mods are updated by their authors.
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Workshop ID: 3711625535
Mod ID: VehicleSetFix
