client: encode the authority by default (grpc#6318)

clientconn.go

@@ -1870,7 +1870,12 @@ func (cc *ClientConn) determineAuthority() error {
  // the channel authority given the user's dial target. For resolvers
  // which don't implement this interface, we will use the endpoint from
  // "scheme://authority/endpoint" as the default authority.
- cc.authority = endpoint
+
+ // Path escape the endpoint to handle use cases where the endpoint
+ // might not be a valid authority by default.
+ // For example an endpoint which has multiple paths like
+ // 'a/b/c', which is not a valid authority by default.
+ cc.authority = url.PathEscape(endpoint)
  }
  channelz.Infof(logger, cc.channelzID, "Channel authority set to %q", cc.authority)
  return nil

test/authority_test.go

@@ -126,7 +126,7 @@ var authorityTests = []authorityTest{
  name: "UnixPassthrough",
  address: "/tmp/sock.sock",
  target: "passthrough:///unix:///tmp/sock.sock",
- authority: "unix:///tmp/sock.sock",
+ authority: "unix:%2F%2F%2Ftmp%2Fsock.sock",
  dialTargetWant: "unix:///tmp/sock.sock",
  },
  {