# Fix for _NamespacePath Concatenation Error

## Issue

After upgrading, Odoo failed to start with the following error:

```
TypeError: unsupported operand type(s) for +: '_NamespacePath' and 'list'
```

This occurred in `odoo/tools/misc.py:169` in the `file_path()` function.

## Root Cause

In Python 3.7+, namespace packages use `_NamespacePath` objects for the `__path__` attribute. This special type cannot be directly concatenated with a Python list using the `+` operator.

The problematic code was:
```python
addons_paths = odoo.addons.__path__ + [root_path]
```

When `odoo.addons.__path__` is a `_NamespacePath` object, attempting to add it to a list `[root_path]` raises a `TypeError`.

## Solution

Convert the `_NamespacePath` to a list before concatenation:

```python
addons_paths = list(odoo.addons.__path__) + [root_path]
```

## File Modified

- `odoo-bringout-oca-ocb-base/odoo/tools/misc.py` line 169

## Related Code

The `file_path()` function is used throughout Odoo to:
- Verify file paths under known `addons_path` directories
- Locate module resources (icons, static files, etc.)
- Validate file access for security purposes

This fix ensures the function can properly construct the list of addon paths to search.

## References

- Python namespace packages: [PEP 420](https://www.python.org/dev/peps/pep-0420/)
- Working commit reference: 3f19943cec2680164696765266fc0cdb4e9220c5