evhttp_encode_uri encodes all reserved characters, including !$'()*+,/:=@ Perviously, some characters not listed as "unreserved" by RFC 3986 (notably "!$'()*+,/:=@") were not encoded by evhttp_encode_uri. This made trouble, especially when encoding path components (where @ and / are bad news) and parameters (where + should get encoded so it doesn't later decode into a space). Spotted by Bas Verhoeven.