[19.0] [FIX] fs_attachment: ignore missing files when migrating to object storage

[ivantodorovich]

In the event an attachment's file is not present in the filestore, Odoo would log an error and return an empty file content: b'' upon reading it's datas.

During a migration to the object storage, that would cause an empty file to be uploaded to the object storage, and the original attachment's checksum to be overwritten with the checksum of the empty file.

This commit fixes this by checking if the file exists before attempting to migrate it, ignoring it otherwise.

[OCA-git-bot]

Hi @lmignon,
some modules you are maintaining are being modified, check this out!

[lmignon]

unfortunately tests are 🔴

[ivantodorovich]

Yeap, it's failing in other PRs as well. Unrelated to this one.
I'll look into it

errors that caused failure (4):
2026-03-02 12:22:23,098 335 ERROR odoo odoo.addons.fs_storage.tests.test_fs_storage: ERROR: TestFSStorage.test_interface_values
Error: Errors detected in log.
Traceback (most recent call last):
  File "/__w/storage/storage/fs_storage/tests/test_fs_storage.py", line 141, in test_interface_values
    with Form(self.env["fs.storage"]) as new_storage:
  File "/opt/odoo/odoo/tests/form.py", line 143, in __init__
    self._init_from_defaults()
  File "/opt/odoo/odoo/tests/form.py", line 339, in _init_from_defaults
    self._perform_onchange()
  File "/opt/odoo/odoo/tests/form.py", line 579, in _perform_onchange
    result = record.onchange(values, field_names, self._view['fields_spec'])
  File "/opt/odoo/odoo/orm/models.py", line 6994, in onchange
    raise NotImplementedError("onchange() is implemented in module 'web'")
NotImplementedError: onchange() is implemented in module 'web'