Examples of errors detected by the V3027 diagnostic

V3027. The variable was utilized in the logical expression before it was verified against null in the same logical expression.

.NET Core Libraries (CoreFX)

V3027 The variable 'start.BaseMapping' was utilized in the logical expression before it was verified against null in the same logical expression. Mappings.cs 598

internal void SetSequence()
{
  if (TypeDesc.IsRoot)
      return;

  StructMapping start = this;

  // find first mapping that does not have the sequence set
  while (!start.BaseMapping.IsSequence &&          // <=
          start.BaseMapping != null    &&          // <=
         !start.BaseMapping.TypeDesc.IsRoot)
      start = start.BaseMapping;
  ....
}

MonoDevelop

V3027 The variable 'oldNode' was utilized in the logical expression before it was verified against null in the same logical expression. MonoDevelop.HexEditor RedBlackTree.cs 167

void Replace (RedBlackTreeNode oldNode, RedBlackTreeNode newNode)
{
  ....
  if (oldNode.parent.left == oldNode ||
      oldNode == null && oldNode.parent.left == null)
  ....
}

IronPython and IronRuby

V3027 The variable 'result' was utilized in the logical expression before it was verified against null in the same logical expression. MutableStringOps.cs 1097

public static MutableString ChompInPlace(....) {
  MutableString result = InternalChomp(self, separator);
  if (result.Equals(self) || result == null) {
    self.RequireNotFrozen();
    return null;
  }
  ....
}

.NET Compiler Platform ("Roslyn")

V3027 The variable 'newType' was utilized in the logical expression before it was verified against null in the same logical expression. AbstractSpeculationAnalyzer.cs 383

private static bool SymbolsAreCompatibleCore(....)
{
  ....
  var type = methodSymbol.ContainingType;
  var newType = newMethodSymbol.ContainingType;
  if ((type != null && type.IsEnumType() &&
       type.EnumUnderlyingType != null &&
       type.EnumUnderlyingType.SpecialType ==
         newType.SpecialType) ||
      (newType != null && newType.IsEnumType() &&
       newType.EnumUnderlyingType != null &&
       newType.EnumUnderlyingType.SpecialType ==
         type.SpecialType))
  {
    return true;
  }
  ....
}

Space Engineers

V3027 The variable 'MySession.ControlledEntity' was utilized in the logical expression before it was verified against null in the same logical expression. Sandbox.Game MyHudWarning.cs 415

private static bool EnergyCritWarningMethod(out MyGuiSounds cue,
                                            out MyStringId text)
{
  ....
  if (MySession.ControlledEntity.Entity is MyCharacter ||
      MySession.ControlledEntity == null)
  ....
}

Mono

V3027 The variable 'm.DeclaringType' was utilized in the logical expression before it was verified against null in the same logical expression. Mono.CodeContracts-net_4_x ContractNodes.cs 211

private bool IsContractMethod (string methodName,
                               Method m,
                               out TypeNode genericArgument)
{
  ....
  return m.Name != null && m.Name == methodName &&
    (m.DeclaringType.Equals (this.ContractClass)       // <=
     || (m.Parameters    != null &&
         m.Parameters.Count == 3 &&
         m.DeclaringType != null &&                    // <=
         m.DeclaringType.Name != ContractClassName));
}

Mono

V3027 The variable 'curr' was utilized in the logical expression before it was verified against null in the same logical expression. Mono.Parallel-net_4_x ConcurrentSkipList.cs 306

Node leftSentinel;
....
IEnumerator<T> GetInternalEnumerator ()
{
  Node curr = leftSentinel;
  while ((curr = curr.Nexts [0]) != rightSentinel &&
         curr != null) {
    ....
  }
}

PowerShell

V3027 The variable 'remoteFileStreams' was utilized in the logical expression before it was verified against null in the same logical expression. System.Management.Automation FileSystemProvider.cs 4126

private void CopyFileFromRemoteSession(....)
{
  ....
  ArrayList remoteFileStreams =
    GetRemoteSourceAlternateStreams(ps, sourceFileFullName);
  if ((remoteFileStreams.Count > 0) &&
      (remoteFileStreams != null))
  ....
}

Orchard CMS

V3027 The variable 'x.Container' was utilized in the logical expression before it was verified against null in the same logical expression. ContainerService.cs 130

public IContentQuery<....> GetContentItemsQuery(....) {
  options = options ?? VersionOptions.Published;
  var query = _contentManager
              .Query<CommonPart, CommonPartRecord>(options);

  query = ids == null ?
        query.Where(x => x.Container.Id == containerId) :
        query.Where(x =>
                     (x.Container.Id == containerId ||
                      x.Container == null) &&
                    ids.Contains(x.Id));

  return query.Join<ContainablePartRecord>();
}

Umbraco

V3027 The variable 'rootDoc' was utilized in the logical expression before it was verified against null in the same logical expression. publishRootDocument.cs 34

public bool Execute(....)
{
  ....
  if (rootDoc.Text.Trim() == documentName.Trim() &&
      rootDoc != null && rootDoc.ContentType != null)
  ....
}

PascalABC.NET

V3027 [CWE-476] The variable 'fn.return_value_type' was utilized in the logical expression before it was verified against null in the same logical expression. NetHelper.cs 1109

private static function_node get_conversion(....)
{
  ....
  function_node fn = si.sym_info as function_node;
  if (.... || fn.return_value_type.original_generic == to || ....
      && fn.return_value_type != null && ....)
  {
    return fn;
  }
  ....
}

Cloudscribe

V3027 The variable 'model' was utilized in the logical expression before it was verified against null in the same logical expression. ConsentController.cs 87

public async Task<IActionResult> Index(ConsentInputModel model)
{
  // user clicked 'no' - send back the standard
  // 'access_denied' response
  if (model.Button == "no")
  {
    response = ConsentResponse.Denied;
  }
  // user clicked 'yes' - validate the data
  else if (model.Button == "yes" && model != null)
  {
    ....
  }
  ....
}

Barotrauma

V3027 The variable 'spawnPosition' was utilized in the logical expression before it was verified against null in the same logical expression. LevelObjectManager.cs 274

private void PlaceObject(LevelObjectPrefab prefab,
                         SpawnPosition spawnPosition,
                         Level level, Level.Cave parentCave = null)
{
  float rotation = 0.0f;
  if (   prefab.AlignWithSurface
      && spawnPosition.Normal.LengthSquared() > 0.001f          // <=
      && spawnPosition != null)                                 // <=
  {
    rotation = MathUtils.VectorToAngle(new Vector2(spawnPosition.Normal.Y,
                                                   spawnPosition.Normal.X));
  }
  ....
}