hide exceptions in server thread

* test/net/ftp/test_ftp.rb (test_tls_connect_timeout): sleeping to give a chance of complete of accept is a timing issue at all.  therefore, simply ignore the exception.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56914 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/net/ftp/test_ftp.rb

@@ -2107,10 +2107,14 @@ EOF
       commands = []
       sock = nil
       @thread = Thread.start do
-        sock = server.accept
-        sock.print("220 (test_ftp).\r\n")
-        commands.push(sock.gets)
-        sock.print("234 AUTH success.\r\n")
+        begin
+          sock = server.accept
+          sock.print("220 (test_ftp).\r\n")
+          commands.push(sock.gets)
+          sock.print("234 AUTH success.\r\n")
+        rescue SystemCallError, IOError
+          # may be raised by broken connection
+        end
       end
       begin
         assert_raise(Net::OpenTimeout) do
@@ -2120,7 +2124,6 @@ EOF
                        open_timeout: 0.1)
         end
       ensure
-        sleep 0.1 # give a chance to complete server.accept
         sock.close if sock
         server.close
       end