Requested feature overview description.
Allow full URLs and filenames in md5: metatag value.

For example, searching for

md5:https://static1.e621.net/data/ff/0f/ff0ff81a2988e20913b9acf0055b1b57.png

and

md5:ff0ff81a2988e20913b9acf0055b1b57.png

would both work.

Why would it be useful?
Would save a small amount of time when searching for e621 image sources since you can paste an image URL in directly instead of having to cut out the md5 string beforehand.

What part(s) of the site page(s) are affected?
Search/index

Regex can be as simple as this to catch md5 in any URL or string format:

/([a-fA-F0-9]{32})/