Examples of errors detected by the V3105 diagnostic

V3105. The 'a' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible.

Microsoft Bot Builder

V3105 The 'parts' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. JwtTokenExtractor.cs 60

public async Task<ClaimsIdentity>
GetIdentityAsync(string authorizationHeader)
{
  ....
  string[] parts = authorizationHeader?.Split(' ');
  if (parts.Length == 2) // <=
    return await GetIdentityAsync(parts[0], parts[1]).
                 ConfigureAwait(false);
  ....
}

.NET Core Libraries (CoreFX)

V3105 The 'versionString' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. RuntimeInformation.cs 29

public static string FrameworkDescription
{
  get
  {
    if (s_frameworkDescription == null)
    {
      string versionString = (string)AppContext.GetData("FX_PRODUCT_VERSION");
      if (versionString == null)
      {
        ....
        versionString
          = typeof(object).Assembly
                          .GetCustomAttribute<
                             AssemblyInformationalVersionAttribute>()
                         ?.InformationalVersion;    // <=
        ....
        int plusIndex = versionString.IndexOf('+'); // <=
        ....
      }
      ....
    }
    ....
  }
}

ML.NET

V3105 The 'mdType' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. PipelineEnsemble.cs 670

private static int CheckKeyLabelColumnCore<T>(....) where T : ....
{
  ....
  for (int i = 1; i < models.Length; i++)
  {
    ....
    var mdType = labelCol.Annotations
                         .Schema
                         .GetColumnOrNull(....)? // <=
                         .Type;

    if (!mdType.Equals(keyValuesType))
      throw env.Except(....);
    ....
  }
  ....
}

ILSpy

V3105 The 'm' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. ILSpy MethodVirtualUsedByAnalyzer.cs 137

static bool ScanMethodBody(IMethod analyzedMethod,
                           IMethod method, MethodBodyBlock methodBody)
{
  ....
  var mainModule = (MetadataModule)method.ParentModule;
  ....
  switch (member.Kind)
  {
    case HandleKind.MethodDefinition:
    case HandleKind.MethodSpecification:
    case HandleKind.MemberReference:
      var m = (mainModule.ResolveEntity(member, genericContext) as IMember)
              ?.MemberDefinition;
      if (   m.MetadataToken == analyzedMethod.MetadataToken               // <=
          && m.ParentModule.PEFile == analyzedMethod.ParentModule.PEFile)  // <=
      {
        return true;
      }
      break;
  }
  ....
}

RavenDB

V3105 The 'newInternalDestinations' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. ReplicationLoader.cs 828

private void HandleInternalReplication(DatabaseRecord newRecord,
                                       List<IDisposable> instancesToDispose)
{
  var newInternalDestinations = newRecord.Topology?.GetDestinations(....);
  ....
  foreach (var item in newInternalDestinations)
    ....
}

Ryujinx

V3105 The 'result' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. Client.cs 213

private byte[] Receive(int clientId, int timeout = 0)
{
    ....

    var result = _client?.Receive(ref endPoint);

    if (result.Length > 0)
    {
        ....
    }
    ....
}

PeachPie

V3105 The 'tinfo' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. Objects.cs 189

public static string get_parent_class(....)
{
  if (caller.Equals(default))
  {
    return null;
  }

  var tinfo = Type.GetTypeFromHandle(caller)?.GetPhpTypeInfo();
  return tinfo.BaseType?.Name;
}

Umbraco

V3105 The 'routeEndpoints' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. RoutableDocumentFilter.cs 198

private bool MatchesEndpoint(string absPath)
{
  IEnumerable<RouteEndpoint> routeEndpoints = _endpointDataSource
    ?.Endpoints
    .OfType<RouteEndpoint>()
    .Where(x =>
    {
      ....
    });

  var routeValues = new RouteValueDictionary();

  RouteEndpoint matchedEndpoint = routeEndpoints
    .Where(e => new TemplateMatcher(
        TemplateParser.Parse(e.RoutePattern.RawText),
        new RouteValueDictionary())
      .TryMatch(absPath, routeValues))
    .OrderBy(c => c.Order)
    .FirstOrDefault();

  return matchedEndpoint != null;
}

Eto.Forms

V3105 The 'fontDesc' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. Eto.Gtk3 RichTextAreaHandler.cs 328

public Font SelectionFont
{
  get
  {
    ....
    Pango.FontDescription fontDesc = null;
    ....
    foreach (var face in family.Faces)
    {
      var faceDesc = face.Describe();
      if (   faceDesc.Weight == weight
          && faceDesc.Style == style
          && faceDesc.Stretch == stretch)
      {
        fontDesc = faceDesc;
        break;
      }
    }
    if (fontDesc == null)
      fontDesc = family.Faces[0]?.Describe();   // <=
    var fontSizeTag = GetTag(FontSizePrefix);
    fontDesc.Size =   fontSizeTag != null       // <=
                    ? fontSizeTag.Size
                    : (int)(Font.Size * Pango.Scale.PangoScale);
    ....
  }
}

Bitwarden

V3105 The '_billingSettings' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. FreshdeskController.cs 47

public class FreshdeskController : Controller
{
  ....
  public FreshdeskController(
    IUserRepository userRepository,
    IOrganizationRepository organizationRepository,
    IOrganizationUserRepository organizationUserRepository,
    IOptions<BillingSettings> billingSettings,
    ILogger<AppleController> logger,
    GlobalSettings globalSettings)
  {
    _billingSettings = billingSettings?.Value;                   // <=
    _userRepository = userRepository;
    _organizationRepository = organizationRepository;
    _organizationUserRepository = organizationUserRepository;
    _logger = logger;
    _globalSettings = globalSettings;
    _freshdeskAuthkey = Convert.ToBase64String(
          Encoding.UTF8
          .GetBytes($"{_billingSettings.FreshdeskApiKey}:X"));   // <=
  }
  ....
}

Bitwarden

V3105 The 'bSettings' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. PayPalIpnClient.cs 22

public PayPalIpnClient(IOptions<BillingSettings> billingSettings)
{
  var bSettings = billingSettings?.Value;
  _ipnUri = new Uri(bSettings.PayPal.Production ?
                      "https://www.paypal.com/cgi-bin/webscr" :
                      "https://www.sandbox.paypal.com/cgi-bin/webscr");
}

AvalonStudio

V3105 The 'mouseDevice' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. TooltipBehavior.cs 173

private async void Timer_Tick(object sender, EventArgs e)
{
  ....
  if (AssociatedObject.IsPointerOver)
  {
    var mouseDevice = (popup.GetVisualRoot() as IInputRoot)?.MouseDevice;
    lastPoint = mouseDevice.GetPosition(AssociatedObject);
    popup.Open();
  }
}

AvalonStudio

V3105 The 'languageServiceProvider' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. CodeEditorViewModel.cs 309

private void RegisterLanguageService(ISourceFile sourceFile)
{
  ....
  var languageServiceProvider = IoC.Get<IStudio>()
                                   .LanguageServiceProviders
                                   .FirstOrDefault(....)?.Value;

  LanguageService = languageServiceProvider.CreateLanguageService();  // <=

  if (LanguageService != null)
  {
    ....
  }
}

OrchardCore

V3105 The 'lastProviders' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. ShellSettingsManager.cs 242

private async Task EnsureConfigurationAsync()
{
  ....
  var lastProviders = (_applicationConfiguration as IConfigurationRoot)
                        ?.Providers.Where(p =>
                        p is EnvironmentVariablesConfigurationProvider ||
                        p is CommandLineConfigurationProvider).ToArray();
  ....
  if (lastProviders.Count() > 0)
  {
    ....
  }
  ....
}

OrchardCore

V3105 The 'externalClaims' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. AccountController.cs 786

private async Task<string> GenerateUsername(ExternalLoginInfo info)
{
  ....
  var externalClaims = info?.Principal.GetSerializableClaims();
  ....
  foreach (var item in _externalLoginHandlers)
  {
    try
    {
      var userName = await item.GenerateUserName(
                      info.LoginProvider, externalClaims.ToArray());
      ....
    }
    ....
  }
  ....
}

.NET MAUI

V3105 The '_visualElement' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. AdaptiveTrigger.cs 69

void AttachEvents()
{
  ....

  _visualElement = VisualState?.VisualStateGroup?.VisualElement;
  if (_visualElement is not null)
    _visualElement.PropertyChanged += OnVisualElementPropertyChanged;

  _window = _visualElement.Window;
  ....
}

Microsoft PowerToys

V3105 The result of null-conditional operator is dereferenced inside the 'AddRange' method. NullReferenceException is possible. Inspect the first argument 'view?.OpenPictureFiles()'. MainViewModel.cs 47

public void Load(IMainView view)
{
  if (_batch.Files.Count == 0)
  {
    _batch.Files.AddRange(view?.OpenPictureFiles()); // <=
  }
  ....
}

public static void AddRange<T>(this ICollection<T> collection,
                               IEnumerable<T> items)
{
  foreach (var item in items) // <=
  {
    collection.Add(item);
  }
}

nopCommerce

V3105 The 'taxRates' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. AvalaraTaxProvider.cs 113

public async Task<....> GetTaxTotalAsync(TaxTotalRequest taxTotalRequest)
{
  ....

  var taxRates = transaction.summary
                            ?.Where(....)
                            .Select(....)
                            .ToList();

  foreach (var taxRate in taxRates)                              // <=
  {
    if (taxTotalResult.TaxRates.ContainsKey(taxRate.Rate))
      taxTotalResult.TaxRates[taxRate.Rate] += taxRate.Value;
    else
      taxTotalResult.TaxRates.Add(taxRate.Rate, taxRate.Value);
  }

  ....
}

Garnet

V3105 The result of null-conditional operator is dereferenced inside the 'InitClients' method. NullReferenceException is possible. Inspect the first argument 'clusterConfig?.Nodes.ToArray()'. ShardedRespOnlineBench.cs 414

public void Run()
{
  PrintClusterConfig();
  Console.WriteLine($"Running benchmark using {opts.Client} client type");

  InitClients(clusterConfig?.Nodes.ToArray());         // <=
  Thread[] workers = InitializeThreadWorkers();
}
....
private void InitClients(ClusterNode[] nodes)
{
  switch (opts.Client)
  {
    case ClientType.GarnetClient:
      gclient = new GarnetClient[nodes.Length];   // <=
      ....
    ....
  }
}

Garnet

V3105 The 'opPercent' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. EmbeddedPerformanceTest.cs 58

public EmbeddedPerformanceTest(...., Options opts, ....)
{
  this.server = server;
  this.opts = opts;
  logger = loggerFactory.CreateLogger("EmbeddedBench");
  opPercent = opts.OpPercent?.ToArray();       // <=
  opWorkload = opts.OpWorkload?.ToArray();     // <=

  if (opPercent.Length != opWorkload.Length)   // <=
    throw new Exception($"....");
  ....
}

Similar errors can be found in some other places:

• V3105 The 'opWorkload' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. EmbeddedPerformanceTest.cs 58

WolvenKit

V3105 The 'whenDoesTheLimitReset' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. LibraryService.cs 332

public async Task<bool> InstallAsync(....)
{
  ....
  try
  {
    ....
  }
  catch (Octokit.ApiException)
  {
    var apiInfo = ghClient.GetLastApiInfo();
    var rateLimit = apiInfo?.RateLimit;
    var howManyRequestsCanIMakePerHour = rateLimit?.Limit;
    var howManyRequestsDoIHaveLeft = rateLimit?.Remaining;
    var whenDoesTheLimitReset = rateLimit?.Reset;

     _logger.LogInformation(
    $"[Update] {howManyRequestsDoIHaveLeft}/{howManyRequestsCanIMakePerHour}" +
    $" - reset: {whenDoesTheLimitReset
    ?? whenDoesTheLimitReset.Value.ToLocalTime()}");
    return false;
  }
}

ScreenToGif

V3105 The 'properties' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. UserSettings.cs 125

var properties = doc.Root?.Elements().Select(GetProperty).ToList();
....
var version = properties?.FirstOrDefault(f => f.Key == "Version")    // <=
                                         ?.Value ?? "0.0";

Migration.Migrate(properties, version);

var resource = new ResourceDictionary {{"Version", All.VersionText}};

foreach (var property in properties)                                 // <=
{
  var value = ParseProperty(property);

  if (value != null && !resource.Contains(property.Key))
    resource.Add(property.Key, value);
}

ScreenToGif

V3105 The 'list' variable was used after it was assigned through null-conditional operator. NullReferenceException is possible. Editor.xaml.cs 4121

if (File.Exists(Path.Combine(pathTemp, "Project.json")))
{
  ....
  using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(json)))
  {
    var ser = new DataContractJsonSerializer(typeof(ProjectInfo));
    var project = ser.ReadObject(ms) as ProjectInfo;

    list = project?.Frames;                                      // <=
  }
}
....
//Shows the ProgressBar
ShowProgress(LocalizationHelper.Get("S.Editor.ImportingFrames"),
                                     list.Count);                // <=