Examples of errors detected by the V3115 diagnostic

V3115. It is not recommended to throw exceptions from 'Equals(object obj)' method.

GitExtensions

V3115 Passing 'null' to 'Equals(object obj)' method should not result in 'NullReferenceException'. Git.hub Organization.cs 14

public override bool Equals(object obj)
{
  return GetHashCode() == obj.GetHashCode(); // <=
}

Similar errors can be found in some other places:

• V3115 Passing 'null' to 'Equals(object obj)' method should not result in 'NullReferenceException'. Git.hub User.cs 16

Media Portal 2

V3115 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. EpisodeInfo.cs 561

public override bool Equals(object obj)
{
  EpisodeInfo other = obj as EpisodeInfo;
  if (obj == null) return false;
  if (TvdbId > 0 && other.TvdbId > 0)
    return TvdbId == other.TvdbId;
  ....
}

Instead of 'other' variable used 'obj' variable for 'null' checking.

PascalABC.NET

V3115 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. ICSharpCode.SharpDevelop ServiceReferenceMapFile.cs 31

public override bool Equals(object obj)
{
  var rhs = obj as ServiceReferenceMapFile;
  return FileName == rhs.FileName;
}

Unity C# reference source code

V3115 CWE-684 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. CurveEditorSelection.cs 74

public override bool Equals(object _other)
{
  CurveSelection other = (CurveSelection)_other;
  return other.curveID == curveID && other.key == key &&
    other.type == type;
}

Similar errors can be found in some other places:

• V3115 CWE-684 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. SpritePackerWindow.cs 40
• V3115 CWE-684 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. PlatformIconField.cs 28
• V3115 CWE-684 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. ShapeEditor.cs 161
• And 2 additional diagnostic messages.

.NET Core Libraries (CoreFX)

V3115 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. CharacterRange.cs 56

public override bool Equals(object obj)
{
  if (obj.GetType() != typeof(CharacterRange))  // <=
    return false;

  CharacterRange cr = (CharacterRange)obj;
  return ((_first == cr.First) && (_length == cr.Length));
}

ONLYOFFICE Community Server

V3115 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. ResCulture.cs 28

public class ResCulture
{
    public string Title { get; set; }
    public string Value { get; set; }
    public bool Available { get; set; }

    public override bool Equals(object obj)
    {
        return Title.Equals(((ResCulture) obj).Title);
    }
    ....
}

.NET 6 libraries

V3115 Passing 'null' to 'Equals' method should not result in 'NullReferenceException'. FilePatternMatch.cs 61

public override bool Equals(object obj)
{
  return Equals((FilePatternMatch) obj);
}

MudBlazor

V3115 Passing 'null' to '==' operator should not result in 'NullReferenceException'. ResizeOptions.cs 34

public static bool operator ==(ResizeOptions l, ResizeOptions r)
                                                       => l.Equals(r);

public static bool operator !=(ResizeOptions l, ResizeOptions r)
                                                       => !l.Equals(r);

Similar errors can be found in some other places:

• V3115 Passing 'null' to '!=' operator should not result in 'NullReferenceException'. ResizeOptions.cs 35