rust protover: match the C implementation on empty-str cases

Empty versions lists are permitted; empty keywords are not.

rust protover: match the C implementation on empty-str cases
5af03c1e · Nick Mathewson · b58a2feb · 5af03c1e
Commit 5af03c1e authored Feb 15, 2018 by Nick Mathewson
--- a/src/rust/protover/protover.rs
+++ b/src/rust/protover/protover.rs
@@ -193,10 +193,6 @@ impl Versions {
    fn from_version_string(
        version_string: &str,
    ) -> Result<Self, &'static str> {
-        if version_string.is_empty() {
-            return Err("version string is empty");
-        }
-
        let mut versions = HashSet::<Version>::new();

        for piece in version_string.split(",") {
@@ -204,6 +200,8 @@ impl Versions {
                for p in expand_version_range(piece)? {
                    versions.insert(p);
                }
+            } else if piece == "" {
+                continue;
            } else {
                let v = u32::from_str(piece).or(
                    Err("invalid protocol entry"),
@@ -456,6 +454,10 @@ fn expand_version_range(range: &str) -> Result<Range<u32>, &'static str> {
        return Err("protocol range value out of range");
    }

+    if lower > higher {
+        return Err("protocol range is badly formed");
+    }
+
    // We can use inclusive range syntax when it becomes stable.
    let result = lower..higher + 1;

@@ -583,6 +585,7 @@ fn parse_protocols_from_string_with_no_validation<'a>(
        let mut parts = subproto.splitn(2, "=");

        let name = match parts.next() {
+            Some("") => return Err("invalid protover entry"),
            Some(n) => n,
            None => return Err("invalid protover entry"),
        };
@@ -650,7 +653,6 @@ pub fn compute_vote(
                Ok(result) => result,
                Err(_) => continue,
            };
-
        for (protocol, versions) in this_vote {
            let supported_vers: &mut HashMap<Version, usize> =
                all_count.entry(protocol).or_insert(HashMap::new());
@@ -794,7 +796,6 @@ mod test {

        use super::Versions;

-        assert_eq!(Err("version string is empty"), Versions::from_version_string(""));
        assert_eq!(Err("invalid protocol entry"), Versions::from_version_string("a,b"));
        assert_eq!(Err("invalid protocol entry"), Versions::from_version_string("1,!"));

@@ -838,7 +839,7 @@ mod test {
        use super::contains_only_supported_protocols;

        assert_eq!(false, contains_only_supported_protocols(""));
-        assert_eq!(false, contains_only_supported_protocols("Cons="));
+        assert_eq!(true, contains_only_supported_protocols("Cons="));
        assert_eq!(true, contains_only_supported_protocols("Cons=1"));
        assert_eq!(false, contains_only_supported_protocols("Cons=0"));
        assert_eq!(false, contains_only_supported_protocols("Cons=0-1"));