Percent-decode incoming queries

[neumark]

headers cannot contain special characters such as newlines (as is described in GH issue #104). The solution is to percent-encode (aka: encodeURIComponent()) the query string. Encoding is not mandatory, some characters like the space are HTTP header-safe, these characters can be sent both as they are or percent encoded (e.g. %20 for space).

[mildbyte]

Nice, it also looks like we're already importing this as a transitive dependency (so it's not going to result in us pulling in extra code)

~/seafowl $ cargo tree | grep percent
│   │   │   │   ├── percent-encoding v2.2.0
│   │   │   │   │   ├── percent-encoding v2.2.0
│   │   │   │   │   │   │   └── percent-encoding v2.2.0
│   │   │   │   │   │   ├── percent-encoding v2.2.0
│   │   ├── percent-encoding v2.2.0
│           └── percent-encoding v2.2.0
│   ├── percent-encoding v2.2.0
    │   │   ├── percent-encoding v2.2.0

[mildbyte]

Instead of using unwrap(), you should use the ? operator to bail out with an Err value and safely extract the Ok value otherwise:

Suggested change

	let decoded_query = percent_decode_str(&raw_query).decode_utf8();
	if decoded_query.is_err() {
	return Err(ApiError::QueryDecodeError);
	}
	let hash_str = str_to_hex_hash(&decoded_query.as_ref().unwrap());
	let decoded_query = percent_decode_str(&raw_query).decode_utf8().map_err(|_| ApiError::QueryDecodeError)?;
	let hash_str = str_to_hex_hash(decoded_query);

(decoded_query should have the type String going ahead, so you don't need unwrap() which will panic at runtime if it encounters an Error value)