Server automatically buys Joja Membership on Day 3

[ColderCoffeee]

Describe the bug

I'm currently playing with my friends and Mods enabled. We're using following Mods:

• SMAPI
• Content Patcher
• Farm Type Manager
• Stardew Valley Expended
• Immersive Farm 2

When we first start the Server, everything is normal and runs fine until Day 3. On this day, when you wake up, you automatically receive the money needed to buy the membership and the Server buys it, which completely ruins the experience IMO, and we don't want to play like that.

Steps to reproduce

Download the Mods and put them into your /var/lib/docker/volumes/stardewvalley_game/_data/Mods directory.
Then add the mod path to your environment docker-compile.yml like this:

• ./mods:/home/stardew/stardewvalley/stardewmods

This will load the mods into your game. Then play until Day 3 and there you go.

Expected behavior

It shouldn't buy the membership automatically.

Additional context

No response

Final checks

• Read the contribution guide.
• Check existing issues.

[MeisnerWest]

Any update on this? Currently playing with friends, didn't realize what the jojo mart membership was and had to do a huge rollback. Best bandaid we found was to disable the automated host, sleep him manually, save frequently for now. Is there a config somewhere that does this that can be edited easily? This happened in the early summer, could have been day three. If we need to leave a server run to get a log file let me know and I will assist however I can. Thanks

[CRISPRCas]

Hi all,

I've also encountered this bug and have performed a detailed analysis. For those looking for an immediate solution, a patched DLL is available. For developers or those interested in the technical details, a full root cause analysis and manual patching guide are provided below.

---

TL;DR: The Quick Fix

The bug is caused by a single incorrect instruction in the mod's code. To fix it, you can simply replace the faulty file.

1. Download the patched file: JunimoServer.dll.zip
2. Replace the DLL: Copy the downloaded JunimoServer.dll into your server's mod directory, overwriting the original. The typical path inside the container is /data/Mods/JunimoServer/JunimoServer.dll.
3. Docker/Kubernetes Users: Restart the container to apply the patch. Make sure your /data/Mods directory is on a persistent volume. Otherwise, the fix will be lost when the container is redeployed.

---

Technical Root Cause Analysis

The issue stems from a logical error in the pre-compiled JunimoServer.dll. The project's docker/Dockerfile (line 101) copies a pre-built .output/mods directory into the final container:

# docker/Dockerfile:101
COPY .output/mods /data/Mods

This means that even if the source code is correct in the repository, the running container uses a pre-compiled DLL with the bug. Therefore, the DLL itself must be patched. Since I did not have the .NET 6 development environment required to recompile the mod from source, the solution presented here involves patching the binary directly.

1. Trigger Condition

The event is triggered at 6:30 AM on any day when the player's total money is 10,000g or more. The call originates from AlwaysOn.cs:

// Source: mod/JunimoServer/Services/AlwaysOnServer/AlwaysOn.cs:179
else if (Game1.timeOfDay == 630)
{
    // ...
    HandleJojaMarket(); 
}

2. Root Cause: Inverted Conditional Logic

The HandleJojaMarket method contains a logical flaw. It is intended to exit early if the game is a Community Center run, but the if condition is inverted.

// Source: mod/JunimoServer/Services/AlwaysOnServer/AlwaysOn.cs:564
private void HandleJojaMarket()
{
    // The '!' is the source of the bug.
    // This should be 'if (Config.IsCommunityCenterRun)', which would correctly
    // exit if it's a Community Center run.
    if (!Config.IsCommunityCenterRun) 
    {
        return;
    }
    // Because of the '!', Community Center runs proceed to the purchase logic below.
}

The ! negation causes the method to only return on a Joja run. Consequently, any save file configured for a Community Center run is incorrectly forced through the Joja purchase logic.

---

Guide: How to Manually Patch the DLL

To fix this, we need to change a single byte in the compiled DLL to flip the conditional branch instruction from "branch if false" to "branch if true".

1. Decompilation with ILSpy

Decompiling JunimoServer.dll reveals the Intermediate Language (IL) for the faulty if statement:

// Method begins at RVA 0xa69c
...
IL_0007: callvirt    instance bool ...::get_IsCommunityCenterRun()
IL_000c: ldc.i4.0    // Push 0 (false) onto the stack
IL_000d: ceq         // Compare: IsCommunityCenterRun == false?
IL_000f: ldc.i4.0
IL_0010: ceq
IL_0011: brfalse.s  IL_0019 // The bug: Branches if the comparison result is false.

When IsCommunityCenterRun is true, the ceq operation at IL_000d results in false. The brfalse.s instruction then causes the program to take the branch, skipping the return statement and proceeding with the purchase. We must change this instruction to brtrue.s.

2. Locating the File Offset

To find this instruction in a hex editor, the method's Relative Virtual Address (RVA) must be converted to a file offset.

• Method RVA (from ILSpy): 0xa69c
• .text Section Virtual Address (from a PE viewer): 0x2000
• .text Section File Offset (from a PE viewer): 0x200
• Calculation: (Method RVA - Section VA) + Section Offset
• File Offset: (0xa69c - 0x2000) + 0x200 = 0x889c

3. Applying the Binary Patch

The sequence of bytes corresponding to the IL instructions from ldc.i4.0 to brfalse.s was found near the method's start offset.

• The target byte sequence starts at file offset 0x88b4.
• Original bytes: 16 FE 01 0A 06 2C
• The byte to change is the last one: 2C, which is the opcode for brfalse.s.
• This must be changed to 2D, the opcode for brtrue.s.

Summary of Steps:

1. Open JunimoServer.dll in a hex editor (e.g., HxD, Hex Fiend).
2. Go to file offset (address) 0x88b4.
3. Verify the byte at this location is 16. The full sequence should be 16 FE 01 0A 06 2C.
4. Change the final byte of this sequence from 2C to 2D.
5. Save the modified file and replace the original on your server.

This change ensures the program correctly branches (and executes the return) when IsCommunityCenterRun is true, thus fixing the bug.

Disclaimer:
After applying this patch and rolling back my save, the bug did not reoccur during subsequent gameplay. However, please be aware that modifying DLL files with a binary editor is inherently risky. This method is not guaranteed to be a perfect fix and could potentially cause other unforeseen issues. Use this workaround at your own risk.

[CRISPRCas]

Further Discussion

Here are a couple of points for those considering alternative ways to handle this bug:

1. For a Community Center run without applying the patch:

You can avoid the bug by bypassing its trigger condition: ensure your total money is not over 10,000g at 6:30 AM. In other words, try not to leave that much gold in your wallet overnight.

However, a potential issue remains. The code that attempts the Joja purchase seems to run even after the Community Center is complete. This means if you finish the Community Center and later accumulate over 10,000g, the bot might still try to buy the membership. I am uncertain if this purchase can actually override a completed Community Center, but based on the code, it seems possible. If anyone has tested this scenario, please share your findings.

2. If you intend to follow the Joja route:

There is likely no need to apply this patch, as the bug automates your intended path. The only edge case might be if you managed to complete the Community Center while keeping your funds low, which could potentially cause the automatic purchase to fail later. However, once the Joja membership is purchased, you no longer need to worry about this interaction, as the Community Center route will be permanently locked.

[JulianVallee]

@CRISPRCas Wow, thanks a lot for the detailed write-up and the pin-point hotfix, very nice!

Currently in a bit of a cleanup phase after not having any time for the project, so definitely merging your fix for the next release.