#735 Prevent modification of the user root folder.

[adiroiban]

Scope

Fixes #735

Update the filesystem handler to prevent operation on the root folder.

Changes

Add a helper to raise an exception.
Guard all operations that can mutate the root.

Todo

• Add automated tests

How to try and test the changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[greptile-apps]

Prompt To Fix All With AI

Fix the following 2 code review issues. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 2
src/chevah_compat/unix_filesystem.py:222-224
**Unreachable legacy root check**

The `if path == '/'` guard (line 224) is now dead code. `_rejectRoot` at the top of this method calls `isRoot`, which already raises `CompatError(1009, ...)` before execution reaches the old check. The two checks also emit different error messages, which could be confusing during debugging if the legacy block were ever reachable.

### Issue 2 of 2
src/chevah_compat/posix_filesystem.py:390-396
**Case-insensitive comparison applied to POSIX paths**

`isRoot` uses `.lower()` on both paths unconditionally. On case-sensitive POSIX filesystems (Linux ext4, etc.), a virtual root configured as `/Home/sftp_root` and a path `/home/sftp_root` would be considered equal, incorrectly blocking operations on the distinct lowercase path. Consider limiting the case-insensitive fold to Windows only, or using `os.path.normcase` which already applies `.lower()` on Windows and is a no-op on POSIX.

```suggestion
        return os.path.normcase(root) == os.path.normcase(path)
```

_{Reviews (1): Last reviewed commit: "Initial implementation." | Re-trigger Greptile}

[greptile-apps]

Unreachable legacy root check

The if path == '/' guard (line 224) is now dead code. _rejectRoot at the top of this method calls isRoot, which already raises CompatError(1009, ...) before execution reaches the old check. The two checks also emit different error messages, which could be confusing during debugging if the legacy block were ever reachable.

Prompt To Fix With AI

This is a comment left during a code review.
Path: src/chevah_compat/unix_filesystem.py
Line: 222-224

Comment:
**Unreachable legacy root check**

The `if path == '/'` guard (line 224) is now dead code. `_rejectRoot` at the top of this method calls `isRoot`, which already raises `CompatError(1009, ...)` before execution reaches the old check. The two checks also emit different error messages, which could be confusing during debugging if the legacy block were ever reachable.

How can I resolve this? If you propose a fix, please make it concise.

[greptile-apps]

Case-insensitive comparison applied to POSIX paths

isRoot uses .lower() on both paths unconditionally. On case-sensitive POSIX filesystems (Linux ext4, etc.), a virtual root configured as /Home/sftp_root and a path /home/sftp_root would be considered equal, incorrectly blocking operations on the distinct lowercase path. Consider limiting the case-insensitive fold to Windows only, or using os.path.normcase which already applies .lower() on Windows and is a no-op on POSIX.

Suggested change

	def isRoot(self, segments):
	"""
	See `ILocalFilesystem`.
	"""
	path = self.getRealPathFromSegments(segments, include_virtual=False)
	root = self.getRealPathFromSegments([], include_virtual=False)
	return root.lower() == path.lower()
	return os.path.normcase(root) == os.path.normcase(path)

Prompt To Fix With AI

This is a comment left during a code review.
Path: src/chevah_compat/posix_filesystem.py
Line: 390-396

Comment:
**Case-insensitive comparison applied to POSIX paths**

`isRoot` uses `.lower()` on both paths unconditionally. On case-sensitive POSIX filesystems (Linux ext4, etc.), a virtual root configured as `/Home/sftp_root` and a path `/home/sftp_root` would be considered equal, incorrectly blocking operations on the distinct lowercase path. Consider limiting the case-insensitive fold to Windows only, or using `os.path.normcase` which already applies `.lower()` on Windows and is a no-op on POSIX.

```suggestion
        return os.path.normcase(root) == os.path.normcase(path)
```

How can I resolve this? If you propose a fix, please make it concise.