ensure rated ease in range

rslib/src/search/parser.rs

@@ -279,11 +279,19 @@ fn parse_flag(s: &str) -> ParseResult<SearchNode<'static>> {
 }
 
 /// eg rated:3 or rated:10:2
+/// second arg must be between 1-4
 fn parse_rated(val: &str) -> ParseResult<SearchNode<'static>> {
     let mut it = val.splitn(2, ':');
     let days = it.next().unwrap().parse()?;
     let ease = match it.next() {
-        Some(v) => Some(v.parse()?),
+        Some(v) => {
+            let n: u8 = v.parse()?;
+            if n < 5 && n > 0 {
+                Some(n)
+            } else {
+                return Err(ParseError {});
+            }
+        }
         None => None,
     };