disallow "+" in repo names

src/atom/parsers.rs

@@ -240,7 +240,7 @@ impl<'a> Parseable<'a, &'a str> for Repo {
     fn parser() -> Self::Parser {
         let start = ascii_alphanumeric().or(one_of("_".chars()));
         let rest = ascii_alphanumeric()
-            .or(one_of("+_-".chars()))
+            .or(one_of("_-".chars()))
             .repeated()
             .many();
 
@@ -579,6 +579,7 @@ mod test {
             ">=dev-libs/libgee-0-8.5:0..8=",
             "<dev-haskell/wai-3.3:=[]",
             ">=kde-frameworks/kcrash-2.16.0:6*",
+            "0-f/merreka+m::k+",
         ];
 
         for atom in atoms {