Fix debugger launch failure with spaces in interpreter path (regression from #964)

[ZA139]

Problem

The debugger fails to start (ENOENT error) when the Python interpreter path contains spaces, such as C:\Program Files\Python312\python.exe. This is a regression introduced in version 2026.4.0.

Root Cause

PR #964 unconditionally applied shell-style quoting via fileToCommandArgumentForPythonExt() to wrap the interpreter executable path before passing it to DebugAdapterExecutable.

However, DebugAdapterExecutable internally uses child_process.spawn() in a non-shell environment. In this mode:

• Literal quote characters are treated as part of the filename rather than delimiters
• This causes the OS to look for a file literally named "C:\...\python.exe" (including the quotes)
• Result: ENOENT: file not found

Solution

Remove the shell-style quoting step for the executable path. child_process.spawn() correctly handles spaces in paths via array-based argument passing and does not require manual quoting.

Changes

1. factory.ts: Remove fileToCommandArgumentForPythonExt(executable) call and replace with explanatory comment
2. factory.unit.test.ts: Update two test cases to expect unquoted paths instead of quoted paths

Testing

• Both "interpreter path with spaces" test cases now verify that paths are passed without quotes
• The tests cover both default adapter path and custom debugAdapterPath scenarios

Related Issues

• Fixes Latest release version of the debugger will not start the debugging process #1013
• Regression from Always quote Python executable path #964

[rchiodo]

Isn't this breaking the original fix in a shell environment? Seems like fileToCommandArgumentForPythonExt should have some way of checking how the launch is going to happen.

[ZA139]

Isn't this breaking the original fix in a shell environment? Seems like fileToCommandArgumentForPythonExt should have some way of checking how the launch is going to happen.

Yep, totally agreed — simply removing fileToCommandArgumentForPythonExt is not sufficient.
The correct fix should depend on whether spawn is running in a shell environment:

• If options.shell === true, we need quotes to handle spaces correctly.
• If options.shell === false (default), we must avoid quotes to prevent ENOENT.

So instead of removing the helper entirely, we should update fileToCommandArgumentForPythonExt to accept a isShell flag and return the path accordingly.

[rchiodo]

I'm not sure if it's a shell environment. It's just whether or not this command is a bat/cmd file.
https://github.com/microsoft/vscode/blob/main/src/vs/workbench/contrib/debug/node/debugAdapter.ts#L173-L180

So maybe this is the correct fix.