[multistream-select] Temporarily disable "parallel" negotiation. (#1807)

* [multistream-select] Temp. disable "parallel" negotiation.

In order to later change the "ls" responses for spec-compliance.

* Update version.

* Update misc/multistream-select/CHANGELOG.md

Co-authored-by: Max Inden <mail@max-inden.de>

Co-authored-by: Max Inden <mail@max-inden.de>

misc/multistream-select/CHANGELOG.md

@@ -1,3 +1,9 @@
+# 0.8.4 [2020-10-20]
+
+- Temporarily disable the internal selection of "parallel" protocol
+  negotiation for the dialer to later change the response format of the "ls"
+  message for spec compliance. See https://github.com/libp2p/rust-libp2p/issues/1795.
+
 # 0.8.3 [2020-10-16]
 
 - Fix a regression resulting in a panic with the `V1Lazy` protocol.

misc/multistream-select/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "multistream-select"
 description = "Multistream-select negotiation protocol for libp2p"
-version = "0.8.3"
+version = "0.8.4"
 authors = ["Parity Technologies <admin@parity.io>"]
 license = "MIT"
 repository = "https://github.com/libp2p/rust-libp2p"

misc/multistream-select/src/dialer_select.rs

@@ -56,12 +56,17 @@ where
     I::Item: AsRef<[u8]>
 {
     let iter = protocols.into_iter();
+    // NOTE: Temporarily disabled "parallel" negotiation in order to correct the
+    // "ls" responses towards interoperability and (new) spec compliance.
+    // See https://github.com/libp2p/rust-libp2p/issues/1795.
+    Either::Left(dialer_select_proto_serial(inner, iter, version))
+
     // We choose between the "serial" and "parallel" strategies based on the number of protocols.
-    if iter.size_hint().1.map(|n| n <= 3).unwrap_or(false) {
-        Either::Left(dialer_select_proto_serial(inner, iter, version))
-    } else {
-        Either::Right(dialer_select_proto_parallel(inner, iter, version))
-    }
+    // if iter.size_hint().1.map(|n| n <= 3).unwrap_or(false) {
+    //    Either::Left(dialer_select_proto_serial(inner, iter, version))
+    // } else {
+    //     Either::Right(dialer_select_proto_parallel(inner, iter, version))
+    // }
 }
 
 /// Future, returned by `dialer_select_proto`, which selects a protocol and dialer
@@ -76,7 +81,7 @@ pub type DialerSelectFuture<R, I> = Either<DialerSelectSeq<R, I>, DialerSelectPa
 /// trying the given list of supported protocols one-by-one.
 ///
 /// This strategy is preferable if the dialer only supports a few protocols.
-pub fn dialer_select_proto_serial<R, I>(
+pub(crate) fn dialer_select_proto_serial<R, I>(
     inner: R,
     protocols: I,
     version: Version
@@ -105,7 +110,7 @@ where
 ///
 /// This strategy may be beneficial if the dialer supports many protocols
 /// and it is unclear whether the remote supports one of the first few.
-pub fn dialer_select_proto_parallel<R, I>(
+pub(crate) fn dialer_select_proto_parallel<R, I>(
     inner: R,
     protocols: I,
     version: Version