Unable to upload properties-utf8 files with method source

[mensinda]

Describe the issue

Uploading Java Properties (UTF-8) files as source does not work.

I already tried

• I've read and searched the documentation.
• I've searched for similar filed issues in this repository.

Steps to reproduce the behavior

1. Create a new project
2. Create a new component (see screenshot)
3. Navigate to the source locale
4. Upload the source property file (see screenshot)
5. Press the Upload button
6. ERROR!

Alternatively:

wlc upload --method source -i source.properties project/component/de

Expected behavior

It is possible to upload Java property files in both the GUI and CLI

Screenshots

Exception traceback

[2025-09-04 13:22:00,028: WARNING/352] Upload error: AttributeError: type object 'PropertiesUtf8Format' has no attribute 'get_msgmerge_args'
[2025-09-04 13:22:00,029: ERROR/352] Upload error
Traceback (most recent call last):
  File "/app/venv/lib/python3.13/site-packages/weblate/api/views.py", line 1783, in file
    not_found, skipped, accepted, total = obj.handle_upload(
                                          ~~~~~~~~~~~~~~~~~^
        request,
        ^^^^^^^^
    ...<5 lines>...
        data["fuzzy"],
        ^^^^^^^^^^^^^^
    )
    ^
  File "/usr/lib/python3.13/contextlib.py", line 85, in inner
    return func(*args, **kwds)
  File "/app/venv/lib/python3.13/site-packages/weblate/trans/models/translation.py", line 1482, in handle_upload
    result = self.handle_source(request, author, fileobj)
  File "/app/venv/lib/python3.13/site-packages/weblate/trans/models/translation.py", line 1297, in handle_source
    args = self.component.file_format_cls.get_msgmerge_args(component)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: type object 'PropertiesUtf8Format' has no attribute 'get_msgmerge_args'
10.42.4.126 - - [04/Sep/2025:15:22:00 +0200] "POST /api/translations/tupspa-tws/38e9efce_tuptws-wmi-api_causes/de/file/ HTTP/1.1" 400 165 "-" "wlc/1.15"

How do you run Weblate?

Docker container

Weblate versions

• Weblate: 5.13
• Django: 5.2.5
• siphashc: 2.5
• translate-toolkit: 3.15.6
• lxml: 6.0.1
• pillow: 11.3.0
• nh3: 0.3.0
• python-dateutil: 2.9.0.post0
• social-auth-core: 4.7.0
• social-auth-app-django: 5.5.1
• django-crispy-forms: 2.4
• oauthlib: 3.3.1
• django-compressor: 4.5.1
• djangorestframework: 3.16.1
• django-filter: 25.1
• django-appconf: 1.1.0
• user-agents: 2.2.0
• filelock: 3.19.1
• RapidFuzz: 3.13.0
• openpyxl: 3.1.5
• celery: 5.5.3
• django-celery-beat: 2.8.1
• kombu: 5.5.4
• translation-finder: 2.23
• weblate-language-data: 2025.8
• html2text: 2025.4.15
• pycairo: 1.28.0
• PyGObject: 3.52.3
• diff-match-patch: 20241021
• requests: 2.32.5
• django-redis: 6.0.0
• hiredis: 3.2.1
• sentry-sdk: 2.35.0
• Cython: 3.1.3
• mistletoe: 1.4.0
• GitPython: 3.1.45
• borgbackup: 1.4.1
• pyparsing: 3.2.3
• ahocorasick_rs: 0.22.2
• charset-normalizer: 3.4.3
• cyrtranslit: 1.1.1
• drf-spectacular: 0.28.0
• Python: 3.13.3
• Git: 2.51.0
• psycopg: 3.2.9
• psycopg-binary: 3.2.9
• phply: 1.2.6
• ruamel.yaml: 0.18.15
• tesserocr: 2.8.0
• boto3: 1.40.16
• aeidon: 1.15
• iniparse: 0.5
• mysqlclient: 2.2.7
• google-cloud-translate: 3.21.1
• openai: 1.101.0
• Mercurial: 7.1
• git-svn: 2.51.0
• git-review: 2.5.0
• Redis server: 8.2.1
• PostgreSQL server: 17.6
• Database backends: django.db.backends.postgresql
• PostgreSQL implementation: psycopg3 (binary)
• Cache backends: default:RedisCache, avatar:FileBasedCache
• Email setup: django.core.mail.backends.dummy.EmailBackend: localhost
• OS encoding: filesystem=utf-8, default=utf-8
• Celery: redis://localhost:6379/1, redis://localhost:6379/1, regular
• Platform: Linux 6.8.0-59-generic (x86_64)

Weblate deploy checks

System check identified some issues:

INFOS:
?: (weblate.I021) Error collection is not set up, it is highly recommended for production use
        HINT: https://docs.weblate.org/en/weblate-5.13/admin/install.html#collecting-errors
?: (weblate.I028) Backups are not configured, it is highly recommended for production use
        HINT: https://docs.weblate.org/en/weblate-5.13/admin/backup.html

System check identified 2 issues (5 silenced).

Additional context

Using mode replace works (in both the GUI and CLI), however, this is not what I want.

[nijel]

It is expected to not work on most formats, AFAIR only gettext currently supports this, see https://docs.weblate.org/en/latest/user/files.html#import-methods.

[nijel]

#16066 improves the error handling in this situation.