RT #116288, test that $socket.read will give us the whole cake

Even if .recv will get several chunks, read will concatenate all these.

S32-io/IO-Socket-INET.pl

@@ -149,6 +149,34 @@
             $sock.close();
         }
     }
+
+    when 6 { # test number 6 - read with parameter
+        if $server_or_client eq 'server' {
+            my $server = IO::Socket::INET.new(:localhost($host), :localport($port), :listen);
+            my $fd = open( $server_ready_flag_fn, :w );
+            $fd.close();
+            while my $client = $server.accept() {
+                # send 4 packets á 4096 bytes
+                for ^4 {
+                    $client.send( $_ x 4096 );
+                    sleep 1;
+                }
+                $client.close();
+            }
+        }
+        else {
+            until $server_ready_flag_fn.IO ~~ :e { sleep(0.1) }
+            unlink $server_ready_flag_fn;
+            my $sock = IO::Socket::INET.new(:$host, :$port);
+            # .read will give us 16kB of data even it recvs several chunks of smaller size
+            my $collected = $sock.read( 4096 * 4 );
+            say $collected.at_pos( 0 ).chr;
+            say $collected.at_pos( 4096 * 4 - 1 ).chr;
+            say $collected.bytes;
+            $sock.close();
+        }
+    }
+
 }
 
 =begin pod

S32-io/IO-Socket-INET.t

@@ -1,7 +1,7 @@
 use v6;
 use Test;
 
-plan 16;
+plan 19;
 
 # L<S32::IO/IO::Socket::INET>
 
@@ -114,6 +114,18 @@ if $*OS eq any <linux darwin solaris MSWin32> { # please add more valid OS names
     is $expected[$i++], 'O frabjous day', '! separator not at end of string';
     is $expected[$i++], ' Callooh', 'Multiple separators not at end of string';
     is $expected[$i++], ' Callay', '! separator at end of string';
+
+    # test 6 tests read with a parameter
+    if $is-win {
+        $received = qqx{t\\spec\\S32-io\\IO-Socket-INET.bat 6 $port};
+    } else {
+        $received = qqx{sh t/spec/S32-io/IO-Socket-INET.sh 6 $port};
+    }
+    $expected = $received.split("\n");
+    $i = 0;
+    is $expected[$i++], '0', 'received first character';
+    is $expected[$i++], '3', 'received last character';
+    is $expected[$i++], 4096 * 4, 'total amount ';
 }
 else {
     skip "OS '$*OS' shell support not confirmed", 1;