only run the admin server if admin-port is specified

sdk/lib/_internal/pub_generated/lib/src/command/serve.dart

 library pub.command.serve;
 import 'dart:async';
 import 'dart:math' as math;
 import 'package:barback/barback.dart';
 import '../barback/asset_environment.dart';
 import '../barback/pub_package_provider.dart';
 import '../log.dart' as log;
 import '../utils.dart';
 import 'barback.dart';
 final _arrow = getSpecial('\u2192', '=>');
@@ skipping 49 matching lines @@
                 entrypoint,
                 mode,
                 watcherType: watcherType,
                 hostname: hostname,
                 basePort: port,
                 useDart2JS: useDart2JS).then((x2) {
               try {
                 var environment = x2;
                 var directoryLength =
                     sourceDirectories.map(((dir) => dir.length)).reduce(math.max);
-                environment.startAdminServer(adminPort).then((x3) {
-                  try {
-                    var server = x3;
-                    server.results.listen(((_) {
-                      assert(false);
-                    }), onError: _fatalError);
-                    join2() {
-                      environment.pauseUpdates();
-                      var it0 = sourceDirectories.iterator;
-                      break0(x7) {
-                        environment.barback.errors.listen(((error) {
-                          log.error(log.red("Build error:\n$error"));
-                        }));
-                        environment.barback.results.listen(((result) {
-                          if (result.succeeded) {
-                            log.message(
-                                "Build completed ${log.green('successfully')}");
-                          } else {
-                            log.message(
-                                "Build completed with " "${log.red(result.errors.length)} errors.");
-                          }
-                        }), onError: _fatalError);
-                        environment.resumeUpdates();
-                        _completer.future.then((x4) {
-                          try {
-                            x4;
-                            completer0.complete(null);
-                          } catch (e2) {
-                            completer0.completeError(e2);
-                          }
-                        }, onError: (e3) {
-                          completer0.completeError(e3);
+                join2() {
+                  join3() {
+                    environment.pauseUpdates();
+                    var it0 = sourceDirectories.iterator;
+                    break0(x6) {
+                      environment.barback.errors.listen(((error) {
+                        log.error(log.red("Build error:\n$error"));
+                      }));
+                      environment.barback.results.listen(((result) {
+                        if (result.succeeded) {
+                          log.message(
+                              "Build completed ${log.green('successfully')}");
+                        } else {
+                          log.message(
+                              "Build completed with " "${log.red(result.errors.length)} errors.");
+                        }
+                      }), onError: _fatalError);
+                      environment.resumeUpdates();
+                      _completer.future.then((x3) {
+                        try {
+                          x3;
+                          completer0.complete(null);
+                        } catch (e1) {
+                          completer0.completeError(e1);
+                        }
+                      }, onError: (e2) {
+                        completer0.completeError(e2);
+                      });
+                    }
+                    continue0(x7) {
+                      if (it0.moveNext()) {
+                        Future.wait([]).then((x5) {
+                          var directory = it0.current;
+                          _startServer(
+                              environment,
+                              directory,
+                              directoryLength).then((x4) {
+                            try {
+                              x4;
+                              continue0(null);
+                            } catch (e3) {
+                              completer0.completeError(e3);
+                            }
+                          }, onError: (e4) {
+                            completer0.completeError(e4);
+                          });
                         });
+                      } else {
+                        break0(null);
                       }
-                      continue0(x8) {
-                        if (it0.moveNext()) {
-                          Future.wait([]).then((x6) {
-                            var directory = it0.current;
-                            _startServer(
-                                environment,
-                                directory,
-                                directoryLength).then((x5) {
-                              try {
-                                x5;
-                                continue0(null);
-                              } catch (e4) {
-                                completer0.completeError(e4);
-                              }
-                            }, onError: (e5) {
-                              completer0.completeError(e5);
-                            });
-                          });
-                        } else {
-                          break0(null);
-                        }
-                      }
-                      continue0(null);
                     }
-                    if (logAdminUrl) {
-                      log.message(
-                          "Running admin server on " "${log.bold('http://${hostname}:${server.port}')}");
+                    continue0(null);
+                  }
+                  if (logAdminUrl) {
+                    log.message(
+                        "Running admin server on " "${log.bold('http://${hostname}:${server.port}')}");
+                    join3();
+                  } else {
+                    join3();
+                  }
+                }
+                if (adminPort != null) {
+                  environment.startAdminServer(adminPort).then((x8) {
+                    try {
+                      var server = x8;
+                      server.results.listen(((_) {
+                        assert(false);
+                      }), onError: _fatalError);
                       join2();
-                    } else {
-                      join2();
+                    } catch (e5) {
+                      completer0.completeError(e5);
                     }
-                  } catch (e1) {
-                    completer0.completeError(e1);
-                  }
-                }, onError: (e6) {
-                  completer0.completeError(e6);
-                });
+                  }, onError: (e6) {
+                    completer0.completeError(e6);
+                  });
+                } else {
+                  join2();
+                }
               } catch (e0) {
                 completer0.completeError(e0);
               }
             }, onError: (e7) {
               completer0.completeError(e7);
             });
           }
           if (commandOptions['force-poll']) {
             join1(WatcherType.POLLING);
           } else {
@@ skipping 61 matching lines @@
         completer0.completeError(e2);
       }
     });
     return completer0.future;
   }
   void _fatalError(error, [stackTrace]) {
     if (_completer.isCompleted) return;
     _completer.completeError(error, stackTrace);
   }
 }