rust/protover: parse empty string into empty *ProtoEntry

Contrary to what 15e59a1fedf47e7e689e06e5649849552d8b8c0d
said, the C implementation has always accepted an empty string
without complaint. Meanwhile the rust implementation has always
given an error. Make the rust implementation match C.

Also eliminate some more redundant tests.

Fix on 0.3.3.1-alpha.

2 files changed, 11 insertions, 14 deletions

diff --git a/src/rust/protover/protover.rs b/src/rust/protover/protover.rs
index 383a781fdc..14a70cd42b 100644
--- a/src/rust/protover/protover.rs
+++ b/src/rust/protover/protover.rs
@@ -245,6 +245,11 @@ impl FromStr for ProtoEntry {
     /// Otherwise, the `Err` value of this `Result` is a `ProtoverError`.
     fn from_str(protocol_entry: &str) -> Result<ProtoEntry, ProtoverError> {
         let mut proto_entry: ProtoEntry = ProtoEntry::default();
+
+        if protocol_entry.is_empty() {
+            return Ok(proto_entry);
+        }
+
         let entries = protocol_entry.split(' ');
 
         for entry in entries {
@@ -493,6 +498,10 @@ impl UnvalidatedProtoEntry {
     ) -> Result<Vec<(&'a str, &'a str)>, ProtoverError> {
         let mut protovers: Vec<(&str, &str)> = Vec::new();
 
+        if protocol_string.is_empty() {
+            return Ok(protovers);
+        }
+
         for subproto in protocol_string.split(' ') {
             let mut parts = subproto.splitn(2, '=');
 
@@ -851,7 +860,8 @@ mod test {
 
     #[test]
     fn test_protoentry_from_str_empty() {
-        assert_protoentry_is_unparseable!("");
+        assert_protoentry_is_parseable!("");
+        assert!(UnvalidatedProtoEntry::from_str("").is_ok());
     }
 
     #[test]
diff --git a/src/rust/protover/tests/protover.rs b/src/rust/protover/tests/protover.rs
index cf0fb5bd3a..c97810a6f2 100644
--- a/src/rust/protover/tests/protover.rs
+++ b/src/rust/protover/tests/protover.rs
@@ -70,18 +70,6 @@ fn protocol_all_supported_with_one_value() {
 }
 
 #[test]
-#[should_panic]
-fn parse_protocol_unvalidated_with_empty() {
-    let _: UnvalidatedProtoEntry = "".parse().unwrap();
-}
-
-#[test]
-#[should_panic]
-fn parse_protocol_validated_with_empty() {
-    let _: ProtoEntry = "".parse().unwrap();
-}
-
-#[test]
 fn protocol_all_supported_with_three_values() {
     let protocols: UnvalidatedProtoEntry = "LinkAuth=1 Microdesc=1-2 Relay=2".parse().unwrap();
     let unsupported: Option<UnvalidatedProtoEntry> = protocols.all_supported();
@@ -156,7 +144,6 @@ fn parse_protocol_with_unexpected_characters() {
 }
 
 #[test]
-#[should_panic]
 fn protover_compute_vote_returns_empty_for_empty_string() {
     let protocols: &[UnvalidatedProtoEntry] = &["".parse().unwrap()];
     let listed = ProtoverVote::compute(protocols, &1);