Fix #3322: Add missing checks for equality comparison

icsharpcode · Jan 13, 2025 · 82db34d · 82db34d
1 parent b9f5090
commit 82db34d
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Showing 4 changed files with 30 additions and 1 deletion.
diff --git a/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj b/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
@@ -130,6 +130,7 @@
     <Compile Include="ProjectDecompiler\TargetFrameworkTests.cs" />
     <Compile Include="TestAssemblyResolver.cs" />
     <Compile Include="TestCases\ILPretty\MonoFixed.cs" />
+    <Compile Include="TestCases\Pretty\Comparisons.cs" />
     <None Include="TestCases\VBPretty\VBAutomaticEvents.vb" />
     <Compile Include="TestCases\VBPretty\VBAutomaticEvents.cs" />
     <Compile Include="TestCases\VBPretty\VBNonGenericForEach.cs" />

diff --git a/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs b/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs
@@ -586,6 +586,12 @@ public async Task OptionalArguments([ValueSource(nameof(defaultOptions))] Compil
 			await RunForLibrary(cscOptions: cscOptions);
 		}
 
+		[Test]
+		public async Task Comparisons([ValueSource(nameof(defaultOptions))] CompilerOptions cscOptions)
+		{
+			await RunForLibrary(cscOptions: cscOptions);
+		}
+
 		[Test]
 		public async Task ConstantsTests([ValueSource(nameof(defaultOptions))] CompilerOptions cscOptions)
 		{

diff --git a/ICSharpCode.Decompiler.Tests/TestCases/Pretty/Comparisons.cs b/ICSharpCode.Decompiler.Tests/TestCases/Pretty/Comparisons.cs
@@ -0,0 +1,18 @@
+namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
+{
+	public class Comparisons
+	{
+		private class A
+		{
+		}
+
+		private class B
+		{
+		}
+
+		private bool CompareUnrelatedNeedsCast(A a, B b)
+		{
+			return (object)a == b;
+		}
+	}
+}
diff --git a/ICSharpCode.Decompiler/CSharp/Resolver/CSharpResolver.cs b/ICSharpCode.Decompiler/CSharp/Resolver/CSharpResolver.cs
@@ -805,7 +805,11 @@ public ResolveResult ResolveBinaryOperator(BinaryOperatorType op, ResolveResult
 					}
 					if (op == BinaryOperatorType.Equality || op == BinaryOperatorType.InEquality)
 					{
-						if (lhsType.IsReferenceType == true && rhsType.IsReferenceType == true)
+						if (lhsType.IsReferenceType == true && rhsType.IsReferenceType == true
+							&& (conversions.IdentityConversion(lhsType, rhsType)
+								|| conversions.ExplicitConversion(lhsType, rhsType).IsReferenceConversion
+								|| conversions.IdentityConversion(rhsType, lhsType)
+								|| conversions.ExplicitConversion(rhsType, lhsType).IsReferenceConversion))
 						{
 							// If it's a reference comparison
 							if (op == BinaryOperatorType.Equality)