Examples of errors detected by the V3106 diagnostic

V3106. Possibly index is out of bound.

Flax Engine

V3106 Possibly index is out of bound. The '4' index is pointing beyond 'values' bound. Matrix2x2.cs 98

public Matrix2x2(float[] values)
{
  ....
  if (values.Length != 4)
    throw new ArgumentOutOfRangeException(....);

  M11 = values[0];
  M12 = values[1];
  M21 = values[3];
  M22 = values[4];                        // <=
}

FastReport

V3106 Possible negative index value. The value of 'idx' index could reach -1. BarcodeCodabar.cs 70

private int FindBarItem(string c)
{
  for (int i = 0; i < tabelle_cb.Length; i++)
  {
    if (c == tabelle_cb[i].c)
      return i;
  }
  return -1;
}

internal override string GetPattern()
{
  string result = tabelle_cb[FindBarItem("A")].data + "0";

  foreach (char c in text)
  {
    int idx = FindBarItem(c.ToString());
    result += tabelle_cb[idx].data + "0";
  }

  result += tabelle_cb[FindBarItem("B")].data;
  return result;
}

.NET Core Libraries (CoreFX)

V3106 Possibly index is out of bound. The '0' index is pointing beyond '_tables' bound. XMLDiffLoader.cs 277

private ArrayList _tables;
private DataTable GetTable(string tableName, string ns)
{
  ....
  if (_tables.Count == 0)
    return (DataTable)_tables[0];
  ....
}

AvaloniaUI

V3106 Possible negative index value. The value of 'index' index could reach -1. Animator.cs 68

protected T InterpolationHandler(double animationTime, T neutralValue)
{
  ....
  if (kvCount > 2)
  {
    if (animationTime <= 0.0)
    {
      ....
    }
    else if (animationTime >= 1.0)
    {
      ....
    }
    else
    {
      int index = FindClosestBeforeKeyFrame(animationTime);
      firstKeyframe = _convertedKeyframes[index];
    }
    ....
  }
  ....
}

Nethermind

V3106 Possibly index is out of bound. The '0' index is pointing beyond 'bytes' bound. Nethermind.Network ReceiptsMessageSerializer.cs 50

public ReceiptsMessage Deserialize(byte[] bytes)
{
  if (bytes.Length == 0 && bytes[0] == Rlp.OfEmptySequence[0])
    return new ReceiptsMessage(null);
  ....
}

Similar errors can be found in some other places:

• V3106 Possibly index is out of bound. The '0' index is pointing beyond 'typesInGroup' bound. Nethermind.Runner EthereumStepsManager.cs 70

EFCore

V3106 Possible negative index value. The value of 'index' index could reach -1. EFCore CompositePrincipalKeyValueFactory.cs 68

protected virtual IReadOnlyList<IProperty> Properties { get; }
....
public virtual IProperty FindNullPropertyInKeyValues(object[] keyValues)
{
  var index = -1;
  for (var i = 0; i < keyValues.Length; i++)
  {
    if (keyValues[i] == null)
    {
      index = i;
      break;
    }
  }

  return Properties[index];
}

Umbraco

V3106 Possibly index is out of bound. The '2' index is pointing beyond 'm.Arguments' bound. ExpressionVisitorBase.cs 632

protected virtual string VisitMethodCall(MethodCallExpression m)
{
  ....
  case "SqlText":
    ....
    if (m.Arguments.Count == 2)
    {
      var n1 = Visit(m.Arguments[0]);
      var f = m.Arguments[2];
      ....
    }
}

MonoGame

V3106 Possible negative index value. The value of 'i' index could reach -1. MonoGame.Framework.DesktopGL(netstandard2.0) Cue.cs 251

public void Apply3D(AudioListener listener, AudioEmitter emitter)
{
  ....
  var i = FindVariable("Distance");
  _variables[i].SetValue(distance);
  ....
  var j = FindVariable("OrientationAngle");
  _variables[j].SetValue(angle);
  ....
}

Barotrauma

V3106 Possibly index is out of bound. The '0' index is pointing beyond 'Sprites' bound. ParticlePrefab.cs 303

public ParticlePrefab(XElement element, ContentFile file)
{
  ....
  if (CollisionRadius <= 0.0f)
    CollisionRadius = Sprites.Count > 0 ? 1 :
                                          Sprites[0].SourceRect.Width / 2.0f;
}

MassTransit

V3106 Possible negative index value. The value of 'paramCount' index could reach -1. ExpressionCompiler.cs 555

private static void
        ReturnClosureTypeToParamTypesToPool(Type[] closurePlusParamTypes)
{
  var paramCount = closurePlusParamTypes.Length - 1;                  // <=
  if (paramCount != 0 && paramCount < 8)
    Interlocked.Exchange(ref _closureTypePlusParamTypesPool[paramCount],
                         closurePlusParamTypes);
}

MassTransit

V3106 Possible negative index value. The value of 'index' index could reach -1. ExpressionCompiler.cs 1977

public static bool TryEmit(....)
{
  ....
  if ((parent & ParentFlags.InlinedLambdaInvoke) != 0)
  {
    var index = closure.GetLabelOrInvokeIndex(gt.Target); // <=
    var invokeIndex = closure.Labels
                             .Items[index]                // <=
                             .InlinedLambdaInvokeIndex;
    ....
  }
  ....
}

public short GetLabelOrInvokeIndex(object labelTarget)
{
  var count = Labels.Count;
  var items = Labels.Items;
  for (short i = 0; i < count; ++i)
    if (items[i].Target == labelTarget)
        return i;
  return -1;
}

Starlight

V3106 The 1st argument 'AstarPath.active.data.GetGraphIndex(this)' is potentially used inside method to point beyond collection's bounds. NavMeshGenerator.cs 225

protected override IEnumerable<Progress> ScanInternal ()
{
  ....
  TriangleMeshNode.SetNavmeshHolder(AstarPath.active.data.GetGraphIndex(this),
                                    this);
  ....
}

public int GetGraphIndex (NavGraph graph) {
  if (graph == null) throw new System.ArgumentNullException("graph");

  var index = -1;
  if (graphs != null) {
    index = System.Array.IndexOf(graphs, graph);
    if (index == -1) Debug.LogError("Graph doesn't exist");
  }
  return index;
}

public static void SetNavmeshHolder (int graphIndex, INavmeshHolder graph) {
  // We need to lock to make sure that
  // the resize operation is thread safe
  lock (lockObject) {
    if (graphIndex >= _navmeshHolders.Length) {
      var gg = new INavmeshHolder[graphIndex+1];
      _navmeshHolders.CopyTo(gg, 0);
      _navmeshHolders = gg;
    }
    _navmeshHolders[graphIndex] = graph;         // <=
  }
}