[Models] Gracefully handle UNIQUE constraints. #902

lilyp commented 2026年06月30日 09:45:50 +02:00

In Manga.new(), id_ may end up as None if the UNIQUE constraint on
(server_id, slug) is violated. Consequently, manga ends up being None,
and an AttributeError is raised by accessing manga.path.

This is typically the result of using the Explorer to browse a manga already
in the library, leading to an application crash.

Error: An unhandled exception occurs
Traceback (most recent call last):
 File "/path/to/python/site-packages/komikku/explorer/search/__init__.py", line 462, in complete_get
 manga = Manga.new(manga_data, self.server, Settings.get_default().long_strip_detection)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 File "/path/to/python/site-packages/komikku/models/database/mangas.py", line 116, in new
 if not os.path.exists(manga.path):
AttributeError: 'NoneType' object has no attribute 'path'

In Manga.new(), id_ may end up as None if the UNIQUE constraint on (server_id, slug) is violated. Consequently, manga ends up being None, and an AttributeError is raised by accessing manga.path. This is typically the result of using the Explorer to browse a manga already in the library, leading to an application crash. ``` Error: An unhandled exception occurs Traceback (most recent call last): File "/path/to/python/site-packages/komikku/explorer/search/__init__.py", line 462, in complete_get manga = Manga.new(manga_data, self.server, Settings.get_default().long_strip_detection) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/path/to/python/site-packages/komikku/models/database/mangas.py", line 116, in new if not os.path.exists(manga.path): AttributeError: 'NoneType' object has no attribute 'path' ```

valos commented 2026年06月30日 23:05:41 +02:00

Damn, this shouldn't be happening. How did you do that? Is it reproducible? I'd like to understand.

Damn, this shouldn't be happening. How did you do that? Is it reproducible? I'd like to understand.

lilyp commented 2026年07月01日 06:19:44 +02:00

It appears to depend on the server. With dynasty, if I happen to add the same manga twice (any one), the above occurs; with xkcd it curiously doesn't, with Pepper&Carrot and Mangadex it also doesn't. Chances are, something is wrong with the dynasty server, but IMHO applying defense in depth sounds reasonable to me.

It appears to depend on the server. With dynasty, if I happen to add the same manga twice (any one), the above occurs; with xkcd it curiously doesn't, with Pepper&Carrot and Mangadex it also doesn't. Chances are, something is wrong with the dynasty server, but IMHO applying defense in depth sounds reasonable to me.

valos commented 2026年07月02日 08:51:50 +02:00

@lilyp wrote in #902 (comment):

IMHO applying defense in depth sounds reasonable to me.

The problem is that there's already protection in place, so this shouldn't happen at all.
Manga.new() can't be call with a (server_id, slug) that already exists.

See komikku/explorer/search/init.py

@lilyp wrote in https://codeberg.org/valos/Komikku/pulls/902#issuecomment-18366062: > IMHO applying defense in depth sounds reasonable to me. The problem is that there's already protection in place, so this shouldn't happen at all. Manga.new() can't be call with a (server_id, slug) that already exists. See [komikku/explorer/search/__init__.py](https://codeberg.org/valos/Komikku/src/branch/main/komikku/explorer/search/__init__.py#L506)

valos commented 2026年07月05日 02:33:04 +02:00

The problem was caused by the Dynasty server, which modified the slug returned by the search (for chapters only) in get_manga_data method.

See 383b4f7907

The problem was caused by the Dynasty server, which modified the slug returned by the search (for chapters only) in `get_manga_data` method. See 383b4f7907