mintty-liberate

I built this proxy DLL, because on Windows (10) all the git-bash windows stick together on the taskbar. You can move them as a group, but not individual windows, which also means you can't re-order your windows on the taskbar.

This behavior is caused by all instances of mintty sharing the same AppID. This project forces unique IDs for every instance, allowing them to be managed individually.

How it Works

The DLL masquerades as winmm.dll and proxies all API calls to the real system winmm.dll.

1. Injection: When DllMain is called with DLL_PROCESS_ATTACH, the payload executes.
2. Safety Check: It checks if the current process is mintty.exe. If not, it does nothing.
3. Hijacking: Inside mintty.exe, the DLL hijacks the entrypoint by setting a debug breakpoint and adding a Vectored Exception Handler (VEH).
4. AppID Modification:

• From the VEH, it generates a random UUID.
• It hijacks GetProcAddress to intercept SetCurrentProcessExplicitAppUserModelID.
• It calls SetCurrentProcessExplicitAppUserModelID immediately with the random UUID to decouple the window from the group.

Prerequisites

This solution requires you to bypass the standard git-bash.exe wrapper and launch mintty directly.

• Tested Environment: Windows 10 IoT Enterprise 21H2
• Mintty Version: 3.8.1

Installation & Usage

1. Build the Project

1. Run build.bat.
2. Navigate to .projects/vs2022 and open mintty_liberate.sln.
3. Build the Release version.

2. Install the DLL

1. Locate the generated winmm.dll.
2. Drop it into the directory containing mintty.exe (usually C:\Program Files\Git\usr\bin\).
3. Test that it works by starting mintty.exe directly.

3. Update Shortcuts

The standard git-bash.exe launcher will still glue windows together. You must create a shortcut that starts mintty directly using /usr/bin/env.

Create a new shortcut with the following properties:

• Target:

"C:\Program Files\Git\usr\bin\mintty.exe" -e /usr/bin/env.exe MSYSTEM=MINGW64 /usr/bin/bash.exe --login

• Start in:

%HOMEDRIVE%%HOMEPATH%

4. Update Context Menu ("Git Bash Here")

To make the right-click context menu work with separate windows, you need to update the registry command keys.

For Directories: Navigate to: Computer\HKEY_CLASSES_ROOT\Directory\shell\git_shell\command Set the value to:

"C:\Program Files\Git\usr\bin\mintty.exe" --dir "%1" -e /usr/bin/env.exe MSYSTEM=MINGW64 /usr/bin/bash.exe --login

For Backgrounds: Navigate to: Computer\HKEY_CLASSES_ROOT\Directory\background\shell\git_shell\command Set the value to:

"C:\Program Files\Git\usr\bin\mintty.exe" --dir "%V" -e /usr/bin/env.exe MSYSTEM=MINGW64 /usr/bin/bash.exe --login

License

MIT