Initial model download integrity

[w-e-w]

Description

Initial model download integrity

recently they seems to be several instances of for whatever reason the "default auto downlaod model" when no model is found being corrupted on download

the file we download by default is v1-5-pruned-emaonly.safetensors
page url https://huggingface.co/runwayml/stable-diffusion-v1-5/blob/main/v1-5-pruned-emaonly.safetensors
sha256: 6ce0161689b3853acaa03779ec93eafe75a02f4ced659bee03f50797806fa2fa

issue post of corrupted models

• [Bug]: Unable to select a checkpoint model when starting from a clean or existing installation. #15568

Loading weights [ff3a2961a8] from M:\z\models\Stable-diffusion\v1-5-pruned-emaonly.safetensors

• [Bug]: Any error happening after 'commit hash : XXXX' is not related to the launcher. Please report them on Automatic1111's github instead : #15575

Loading weights [7f008929e1] from F:\A1111 Web UI Autoinstaller\stable-diffusion-webui\models\Stable-diffusion\v1-5-pruned-emaonly.safetensors

As corrupted model could have serious consequences causing webui to enter a "unable to switch model loop" it makes sense to check for the Integrity of the file

• see details and possible fix Fix corrupt model initial load loop #15600

---

the download_url_to_file utility we used to download the model will automatically delete the model if the hash does not match

• along with if the hash dose not match and is deleted webui would still be able to launch, just not able to generate images

in these cases users can either retry downloading the model by restarting web UI
download the models manually
or possibly install model downloader extensions to help them download other models

clarification
there is no risk of user files be accidentally deleted
the Integrity check it's only performed on the model that is currently being downloaded

Checklist:

• I have read contributing wiki page
• I have performed a self-review of my own code
• My code follows the style guidelines
• My code passes tests