Test to cover .recv(Inf) on socket.

S32-io/socket-recv-vs-read.t

@@ -1,7 +1,7 @@
 use v6;
 use Test;
 
-plan 11;
+plan 13;
 
 # Covers RT #126315 (which wanted the right thing of recv) and RT #116288
 # (difference between recv and read semantics).
@@ -54,6 +54,13 @@ is $client.recv(2, :bin).decode('ascii'), 'an',
     'recv argument serves as upper limit (bytes)';
 $client.close;
 
+$send-rest = Promise.new;
+$client = IO::Socket::INET.new(:host("$hostname:$port"));
+is $client.recv(Inf), 'first thing', 'recv with Inf works (chars 1)';
+$send-rest.keep(True);
+is $client.recv(Inf), 'another thing', 'recv with Inf works (chars 2)';
+$client.close;
+
 $send-rest = Promise.new;
 my $p = start {
     $client = IO::Socket::INET.new(:host("$hostname:$port"));