Bug overview description.
Using multiple "source:" in a search, breaks the search by only using the last one.

example:source:furaffinity source:tumblr

Same goes for removing one source:

source:furaffinity -source:tumblr

What part(s) of the site page(s) are affected?
Searching .

What is the expected behavior?
It should return posts with both sources.

What actual behavior is given instead?
The first one is excluded from the search.

Can you reproduce the bug every time?
Yep.

What steps did you take to replicate this bug?

Example: source:furaffinity source:tumblr
Example: source:tumblr source:furaffinity
Example: source:furaffinity -source:tumblr
Example: source:tumblr -source:furaffinity

This is part of a larger metabug where search fields that are not tags cannot have more than one value to search for. It applies to all fields and modifiers.

This definitely does make it counterintuitive when users are encouraged to put as many sources as possible, but doing so it makes searching for possible lower quality posts more painful.