When a ComfyUI workflow ends in the core "Save Image (Advanced)" node, ComfyUI finishes the job and saves the image, but Open WebUI returns an empty result, so the chat shows nothing. Image editing workflows such as the Qwen Image Edit template use this node by default.
Open WebUI only collects images from output nodes of type SaveImage and PreviewImage. This adds SaveImageAdvanced to that list. The node reports its files in the same format as SaveImage, so the rest of the download and storage path works unchanged. Generation and editing share this code, so both are fixed.
Fixes#30404
GLOBAL_LOG_LEVEL defaults to INFO, so every log.debug(...) in the backend is discarded, but the message is built first: 187 call sites interpolate their payload into an f-string before the logging call runs, so the work happens on every request and the result is thrown away. The worst one sits in process_chat_payload and stringifies the whole request body, full conversation history included, once per chat completion.
That one line with DEBUG disabled, CPython 3.12:
| conversation | payload | before | after |
| ------------ | ------- | -------- | ------- |
| 4 messages | 1.2 kB | 3.4 us | 0.07 us |
| 20 messages | 17 kB | 24.8 us | 0.07 us |
| 60 messages | 123 kB | 216.6 us | 0.07 us |
The lazy form log.debug('form_data: %s', form_data) hands the payload to record.getMessage(), which the InterceptHandler only reaches once a record has passed the level check. With DEBUG enabled the emitted lines are byte-identical, f'{x=}' sites included: those map to %r. MistralLoader._debug_log callers get the same treatment, since that wrapper already forwards *args.
