[dxrpl]

Summary

sharpen, remove-bg, denoise, upscale-local and enhance-face decoded the client's image with a bare base64.b64decode + Image.open, so a missing, malformed or non-image image ended in an unhandled exception and a 500. They now use the existing _b64_to_pil_image() helper, which harmonize, inpaint and mask already use, so they answer 400 Missing image / 400 Invalid image. The existing 400 No image provided checks in denoise, upscale-local and enhance-face stay as they were. Valid images are processed as before.

Target branch

• This PR targets the correct integration branch: lab in the private maintainer-preview repository, or dev in the public repository. main remains release-curated.

Linked Issue

Fixes #6818

Type of Change

• Bug fix (non-breaking — fixes a confirmed issue)
• New feature (non-breaking — adds new behaviour)
• Breaking change (changes or removes existing behaviour)
• Refactor / cleanup (behaviour unchanged)
• Documentation only
• CI / tooling / configuration

Checklist

• I searched open issues and open PRs — this is not a duplicate.
• This PR targets the correct integration branch (lab in maintainer-preview; dev in the public repository)
• My changes are limited to the scope described above — no unrelated refactors or whitespace changes mixed in.
• I actually ran the app (docker compose up or uvicorn app:app) and verified the change works end-to-end. Type-checks and unit tests are not enough.
• I did not run the app/runtime validation and stated that gap in How to Test. Leave this unchecked when the app-run box above is checked.

How to Test

I ran the branch natively (uvicorn app:app, scratch data dir), logged in as admin, and POSTed {}, {"image":"!!notb64"} and {"image":"aGVsbG8="} to each of the five routes. On dev these gave 500 (12 of the 15 requests; the other 3 were the existing No image provided 400). On this branch all 15 give 400. I did not run the editor UI or a real image through Real-ESRGAN/GFPGAN, because those packages are not installed here. The new tests/test_gallery_image_bad_input.py fails on dev (12 failures) and passes with the change, together with the existing gallery tests.

To check by hand:

1. Start the app and log in.
2. curl -b cj -X POST -H 'content-type: application/json' -d '{"image":"!!notb64"}' localhost:7000/api/image/sharpen (repeat for remove-bg, denoise, upscale-local, enhance-face).
3. Each should return 400 {"detail":"Invalid image"}, not a 500.

Visual / UI changes — REQUIRED if you touched anything that renders

No visual change: the edit only fixes variable scoping so the existing timeout message is reachable. No markup, CSS or styling was touched.

• Screenshot or short clip: not applicable, see above.
• I am not an LLM agent submitting a bulk PR.

Screenshots / clips

The reply bubble after the 120 s timeout, with the fix applied: