Fix bug when updating add-ons automatically - #18971

…ddonImports

_cleanupAddonImports now matches modules on their file path against the
add-on directory, case insensitively and anchored at a path separator.
Modules without a file attribute are skipped.
Add unit tests covering the cleanup.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

…ddonImports

_cleanupAddonImports now matches modules on their file path against the
add-on directory, case insensitively and anchored at a path separator.
Modules without a file attribute are skipped.
Add unit tests covering the cleanup.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Fixup for #18971.
Summary of the issue:

Installing or removing an add-on can run install tasks. These tasks can import modules from the add-on. Python caches every import in sys.modules. NVDA must drop the add-on's modules from that cache afterwards. Otherwise a later import returns the cached old module instead of the file on disk.

Modules the tasks load directly are tracked in _importedAddonModules and dropped reliably. Modules imported indirectly, for example through a relative import inside the add-on, are not tracked. For those, _cleanupAddonImports scans every module imported during the task and drops each one whose file is inside the add-on directory.

That scan has been broken twice:

    Remove add-on modules imported in install tasks to avoid conflicts between add-ons #15967 introduced it reading module.__file__ directly. Modules without a __file__, such as built-in modules, made it crash with AttributeError.
    Fix bug when updating add-ons automatically #18971 fixed that crash by reading module.__name__ instead. A module name is not a file path, so the scan matches nothing. Since 2026.1 it drops nothing.

Result: updating an add-on can break on the first start after the update. The old version's uninstall task runs first and leaves old modules in the cache. The new version then partly imports old code. A second restart of NVDA resolves the situation regardless.
Description of user facing changes:

Updated add-ons that perform install tasks no longer raise intermittent errors on the first start of NVDA after the update.
Description of developer facing changes:

None.
Description of development approach:

The approach of #15967 was the correct one: a module belongs to the add-on when its file is inside the add-on directory. This change returns to matching on the file path and fixes the three defects of that implementation:

    The file is read with getattr(module, "__file__", None). Modules without a __file__ are skipped instead of crashing the scan, so the error fixed by Fix bug when updating add-ons automatically #18971 stays fixed.
    The file path and the add-on directory are compared through os.path.normcase, so case differences match.
    The directory prefix ends with a path separator, so a sibling directory such as myAddonExtra no longer matches myAddon.

Each defect is covered by a unit test. The loop over the tracked modules is unchanged.