Reverse patches appears to be broken

[Meivyn]

Followup of #79 (comment).

HarmonyLib.HarmonyException: IL Compile Error (unknown location) ---> System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
  at Mono.Collections.Generic.Collection`1[T].get_Item (System.Int32 index) [0x00009] in <1f38765308444399b8db490e5065ff6f>:0
  at MonoMod.Utils.Cil.CecilILGenerator._EmitInlineVar (Mono.Cecil.Cil.OpCode opcode, System.Int32 index) [0x0004c] in <119a8e5581064dd58d95959152c2aa57>:0
  at MonoMod.Utils.Cil.CecilILGenerator.Emit (System.Reflection.Emit.OpCode opcode, System.Byte arg) [0x0001d] in <119a8e5581064dd58d95959152c2aa57>:0
  at (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition.EmitOpcodeWithOperand(MonoMod.Utils.Cil.CecilILGenerator,System.Reflection.Emit.OpCode,object)
  at (wrapper delegate-invoke) System.Action`3[MonoMod.Utils.Cil.CecilILGenerator,System.Reflection.Emit.OpCode,System.Object].invoke_void_T1_T2_T3(MonoMod.Utils.Cil.CecilILGenerator,System.Reflection.Emit.OpCode,object)
  at HarmonyLib.Internal.Util.EmitterExtensions.Emit (MonoMod.Utils.Cil.CecilILGenerator il, System.Reflection.Emit.OpCode opcode, System.Object operand) [0x00000] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at HarmonyLib.Internal.Patching.ILManipulator.WriteTo (Mono.Cecil.Cil.MethodBody body, System.Reflection.MethodBase original) [0x0017a] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at HarmonyLib.PatchFunctions+<>c__DisplayClass3_0.<ReversePatch>b__1 (MonoMod.Cil.ILContext ctx) [0x0016f] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at MonoMod.Cil.ILContext.Invoke (MonoMod.Cil.ILContext+Manipulator manip) [0x00092] in <119a8e5581064dd58d95959152c2aa57>:0
  at MonoMod.RuntimeDetour.DetourManager+ManagedDetourState.InvokeManipulator (MonoMod.RuntimeDetour.DetourManager+ILHookEntry entry, Mono.Cecil.MethodDefinition def) [0x0001c] in <667886c0b83048cbaa73a76b37c17c40>:0
  at MonoMod.RuntimeDetour.DetourManager+ManagedDetourState.UpdateEndOfChain () [0x0008b] in <667886c0b83048cbaa73a76b37c17c40>:0
  at MonoMod.RuntimeDetour.DetourManager+ManagedDetourState.AddILHook (MonoMod.RuntimeDetour.DetourManager+SingleILHookState ilhook, System.Boolean takeLock) [0x00079] in <667886c0b83048cbaa73a76b37c17c40>:0
  at MonoMod.RuntimeDetour.ILHook.Apply () [0x00052] in <667886c0b83048cbaa73a76b37c17c40>:0
  at HarmonyLib.PatchFunctions.ReversePatch (HarmonyLib.HarmonyMethod standin, System.Reflection.MethodBase original, System.Reflection.MethodInfo postTranspiler, System.Reflection.MethodInfo postManipulator) [0x0016e] in <0d9c13022e544ce89c806f0f14d8e072>:0
   --- End of inner exception stack trace ---
  at HarmonyLib.PatchClassProcessor.ReportException (System.Exception exception, System.Reflection.MethodBase original) [0x00045] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at HarmonyLib.PatchClassProcessor.Patch () [0x00095] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at HarmonyLib.Harmony.<PatchAll>b__11_0 (System.Type type) [0x00007] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at HarmonyLib.CollectionExtensions.Do[T] (System.Collections.Generic.IEnumerable`1[T] sequence, System.Action`1[T] action) [0x00014] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at HarmonyLib.Harmony.PatchAll (System.Reflection.Assembly assembly) [0x00006] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at HarmonyLib.Harmony.CreateAndPatchAll (System.Reflection.Assembly assembly, System.String harmonyInstanceId) [0x0006a] in <0d9c13022e544ce89c806f0f14d8e072>:0
  at BSPlugin5.Plugin..ctor (IPA.Logging.Logger logger, IPA.Loader.PluginMetadata metadata) [0x0000c] in C:\Users\Meivyn\RiderProjects\BSPlugin5\BSPlugin5\Plugin.cs:22
  at (wrapper dynamic-method) System.Object.lambda_method(System.Runtime.CompilerServices.Closure,IPA.Loader.PluginMetadata)
  at IPA.Loader.PluginExecutor.Create () [0x00009] in C:\Users\Meivyn\repos\BeatSaber-IPA-Reloaded\IPA.Loader\Loader\PluginExecutor.cs:57
  at IPA.Loader.PluginLoader.InitPlugin (IPA.Loader.PluginMetadata meta, System.Collections.Generic.IEnumerable`1[T] alreadyLoaded) [0x001ec] in C:\Users\Meivyn\repos\BeatSaber-IPA-Reloaded\IPA.Loader\Loader\PluginLoader.cs:957

I confirmed that this does happen on non-reorg as well (happens with v2.10.2).

The patched method looks like this:

The patch which is failing is simply returning the same instructions:

[HarmonyPatch(typeof(MainMenuViewController), nameof(MainMenuViewController.HandleMenuButton)]
internal class Patch
{
    [HarmonyReversePatch]
    private static void ReversePatch(MainMenuViewController.MenuButton menuButton)
    {
        throw new NotImplementedException("Reverse patch has not been executed.");

        IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
        {
            return instructions;
        }
    }
}

[crpz1]

Chiming in to say that I'm also having this problem while trying to fix another problem. With a similar setup to above, I get Invalid IL errors whenever ldarg.0 is encountered in the instruction list. Patching the method to use any other instruction in its place results in the above mentioned stack trace.

HarmonyLib.HarmonyException: IL Compile Error (unknown location) ---> System.InvalidProgramException: Invalid IL code in (wrapper dynamic-method) AtlyssUIShortcuts.Patches.PlayerInteractPatch:DMD<AtlyssUIShortcuts.Patches.PlayerInteractPatch::AwakeReversePatch> (): IL_0000: ldarg.0


  at (wrapper managed-to-native) System.RuntimeMethodHandle.GetFunctionPointer(intptr)
  at System.RuntimeMethodHandle.GetFunctionPointer () [0x00000] in <75633565436c42f0a6426b33f0132ade>:0
  at MonoMod.RuntimeDetour.Platforms.DetourRuntimeILPlatform.GetFunctionPointer (System.Reflection.MethodBase method, System.RuntimeMethodHandle handle) [0x00000] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at MonoMod.RuntimeDetour.Platforms.DetourRuntimeILPlatform.GetNativeStart (System.Reflection.MethodBase method) [0x0004d] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at MonoMod.RuntimeDetour.DetourHelper.GetNativeStart (System.Reflection.MethodBase method) [0x00005] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at MonoMod.RuntimeDetour.Detour._TopApply () [0x00025] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at MonoMod.RuntimeDetour.Detour._RefreshChain (System.Reflection.MethodBase method) [0x00149] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at MonoMod.RuntimeDetour.Detour.Apply () [0x00053] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at MonoMod.RuntimeDetour.Detour..ctor (System.Reflection.MethodBase from, System.Reflection.MethodBase to, MonoMod.RuntimeDetour.DetourConfig& config) [0x002e1] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at (wrapper dynamic-method) MonoMod.RuntimeDetour.ILHook+Context.DMD<MonoMod.RuntimeDetour.ILHook+Context::Refresh>(MonoMod.RuntimeDetour.ILHook/Context)
  at (wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition.Trampoline<MonoMod.RuntimeDetour.ILHook+Context::Refresh>?-1965818678(object)
  at HarmonyLib.Internal.RuntimeFixes.StackTraceFixes.OnILChainRefresh (System.Object self) [0x00000] in <474744d65d8e460fa08cd5fd82b5d65f>:0
  at MonoMod.RuntimeDetour.ILHook.Apply () [0x00059] in <4e2760c7517c4ea79c633d67e84b319f>:0
  at HarmonyLib.PatchFunctions.ReversePatch (HarmonyLib.HarmonyMethod standin, System.Reflection.MethodBase original, System.Reflection.MethodInfo postTranspiler, System.Reflection.MethodInfo postManipulator) [0x0015d] in <474744d65d8e460fa08cd5fd82b5d65f>:0
   --- End of inner exception stack trace ---
  at HarmonyLib.PatchClassProcessor.ReportException (System.Exception exception, System.Reflection.MethodBase original) [0x00045] in <474744d65d8e460fa08cd5fd82b5d65f>:0
  at HarmonyLib.PatchClassProcessor.Patch () [0x00095] in <474744d65d8e460fa08cd5fd82b5d65f>:0
  at HarmonyLib.Harmony.<PatchAll>b__11_0 (System.Type type) [0x00007] in <474744d65d8e460fa08cd5fd82b5d65f>:0
  at HarmonyLib.CollectionExtensions.Do[T] (System.Collections.Generic.IEnumerable`1[T] sequence, System.Action`1[T] action) [0x00014] in <474744d65d8e460fa08cd5fd82b5d65f>:0
  at HarmonyLib.Harmony.PatchAll (System.Reflection.Assembly assembly) [0x00006] in <474744d65d8e460fa08cd5fd82b5d65f>:0
  at HarmonyLib.Harmony.PatchAll () [0x0001b] in <474744d65d8e460fa08cd5fd82b5d65f>:0
  at AtlyssUIShortcuts.AtlyssUIShortcuts.Awake () [0x00033] in <c09efbae08994db699a4430e9ea358c2>:0

The following is my patch:

[HarmonyPatch(typeof(PlayerInteract))]
class PlayerInteractPatch
{

    [HarmonyPatch("Awake")]
    [HarmonyReversePatch]
    private static void AwakeReversePatch()
    {
        return;
    }
}

Patch that results in System.ArgumentOutOfRangeException:

[HarmonyPatch("Awake")]
[HarmonyReversePatch]
private static void AwakeReversePatch()
{
    IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
    {
        var list = Transpilers.Manipulator(instructions,
            item => item.opcode == OpCodes.Ldarg_0,
            item =>
            {
                item.opcode = OpCodes.Ldarg;
                item.operand = 0;
            }
        );

        return list;
    }

    return;
}

And finally the method being patched: