radicle/profile: Control socket path for Windows

The `winpipe` crate which is our current best bet for support on Windows
requires that named pipes are at the magical location `\\.pipe\`.

Provide a default on Windows that matches this, and use our freshly
assigned IANA service name for it.

This is a breaking change, as we remove a `pub const`, it should be
reasonably easy to fix by dependents, and probably it was a mistake to
make the default `pub const` as dependents should call `Home::socket`
anyway.

crates/radicle/CHANGELOG.md

@@ -0,0 +1,24 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+
+### Changed
+
+- `radicle::profile::Home::socket` defaults to the path `\\.\pipe\radicle-node`
+  on Windows. The behavior on Unix-like systems has *not* changed.
+
+### Deprecated
+
+### Removed
+
+- `radicle::node::DEFAULT_SOCKET_NAME`, use `radicle::profile::Home::socket`
+  instead.
+
+### Security

crates/radicle/src/node.rs

@@ -53,8 +53,6 @@ pub use timestamp::Timestamp;
 
 /// Peer-to-peer protocol version.
 pub const PROTOCOL_VERSION: u8 = 1;
-/// Default name for control socket file.
-pub const DEFAULT_SOCKET_NAME: &str = "control.sock";
 /// Default radicle protocol port.
 pub const DEFAULT_PORT: u16 = 8776;
 /// Default timeout when waiting for the node to respond with data.

crates/radicle/src/profile.rs

@@ -578,9 +578,32 @@ impl Home {
     }
 
     pub fn socket(&self) -> PathBuf {
-        env::var_os(env::RAD_SOCKET)
-            .map(PathBuf::from)
-            .unwrap_or_else(|| self.node().join(node::DEFAULT_SOCKET_NAME))
+        use env::RAD_SOCKET;
+
+        #[cfg(unix)]
+        const DEFAULT_SOCKET_NAME: &str = "control.sock";
+
+        #[cfg(windows)]
+        const DEFAULT_SOCKET_NAME: &str = r#"\\.\pipe\radicle-node"#;
+
+        match env::var_os(RAD_SOCKET).map(PathBuf::from) {
+            None => {
+                #[cfg(unix)]
+                return self.node().join(DEFAULT_SOCKET_NAME);
+
+                #[cfg(windows)]
+                return PathBuf::from(DEFAULT_SOCKET_NAME);
+            }
+            Some(path) => {
+                #[cfg(windows)]
+                {
+                    const PIPE_PREFIX: &str = r#"\\.\pipe\"#;
+                    assert!(path.starts_with(PIPE_PREFIX), "The value of the environment variable {RAD_SOCKET} ('{}') must start with {PIPE_PREFIX}. This restriction might be relaxed in the future.", path.display());
+                }
+
+                path
+            }
+        }
     }
 
     /// Return a read-write handle to the notifications database.