Exception while decompiling nested tuple deconstruction

[mmusu3]

Input code

class DeconstructErrorTest
{
    struct Data
    {
        public void Deconstruct(out object o1, out object o2)
        {
            o1 = default;
            o2 = default;
        }
    }

    static void Test(KeyValuePair<object, Data> pair)
    {
        var (key, (value, _)) = pair;

        Empty(key);
        Empty(value);
    }

    static void Empty(object o) => _ = o;
}

Erroneous output

Error decompiling @0600009B DeconstructErrorTest.Test
 ---> System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. (Parameter 'index')
   at System.ThrowHelper.ThrowArgumentOutOfRange_IndexMustBeLessException() in offset 0
   at System.Collections.Generic.List`1.get_Item(Int32 index) in offset 9
   at ICSharpCode.Decompiler.IL.InstructionCollection`1.get_Item(Int32 index) in InstructionCollection.cs:line 46
   at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.<VisitDeconstructInstruction>g__ConstructTuple|160_0(MatchInstruction matchInstruction, <>c__DisplayClass160_0&) in ExpressionBuilder.cs:line 4601
   at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.VisitDeconstructInstruction(DeconstructInstruction inst, TranslationContext context) in ExpressionBuilder.cs:line 4583
   at ICSharpCode.Decompiler.IL.DeconstructInstruction.AcceptVisitor[C,T](ILVisitor`2 visitor, C context) in Instructions.cs:line 6729
   at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.Translate(ILInstruction inst, IType typeHint) in ExpressionBuilder.cs:line 163
   at ICSharpCode.Decompiler.CSharp.StatementBuilder.Default(ILInstruction inst) in StatementBuilder.cs:line 91
   at ICSharpCode.Decompiler.IL.ILVisitor`1.VisitDeconstructInstruction(DeconstructInstruction inst) in Instructions.cs:line 7614
   at ICSharpCode.Decompiler.IL.DeconstructInstruction.AcceptVisitor[T](ILVisitor`1 visitor) in Instructions.cs:line 6725
   at ICSharpCode.Decompiler.CSharp.StatementBuilder.Convert(ILInstruction inst) in StatementBuilder.cs:line 80
   at ICSharpCode.Decompiler.CSharp.StatementBuilder.ConvertBlockContainer(BlockStatement blockStatement, BlockContainer container, IEnumerable`1 blocks, Boolean isLoop) in StatementBuilder.cs:line 1443
   at ICSharpCode.Decompiler.CSharp.StatementBuilder.ConvertBlockContainer(BlockContainer container, Boolean isLoop) in StatementBuilder.cs:line 1347
   at ICSharpCode.Decompiler.CSharp.StatementBuilder.VisitBlockContainer(BlockContainer container) in StatementBuilder.cs:line 1233
   at ICSharpCode.Decompiler.IL.BlockContainer.AcceptVisitor[T](ILVisitor`1 visitor) in Instructions.cs:line 850
   at ICSharpCode.Decompiler.CSharp.StatementBuilder.Convert(ILInstruction inst) in StatementBuilder.cs:line 80
   at ICSharpCode.Decompiler.CSharp.StatementBuilder.ConvertAsBlock(ILInstruction inst) in StatementBuilder.cs:line 85
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DecompileBody(IMethod method, EntityDeclaration entityDecl, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1780
-- continuing with outer exception (ICSharpCode.Decompiler.DecompilerException) --
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DecompileBody(IMethod method, EntityDeclaration entityDecl, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1795
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DoDecompile(IMethod method, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1644
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.<>c__DisplayClass75_0.<DoDecompile>g__DoDecompileMember|0(IEntity entity, RecordDecompiler recordDecompiler, PartialTypeInfo partialType) in CSharpDecompiler.cs:line 1519
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DoDecompile(ITypeDefinition typeDef, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1382
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.Decompile(IEnumerable`1 definitions) in CSharpDecompiler.cs:line 1038
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.Decompile(EntityHandle[] definitions) in CSharpDecompiler.cs:line 1010
   at ICSharpCode.ILSpy.CSharpLanguage.DecompileType(ITypeDefinition type, ITextOutput output, DecompilationOptions options) in offset 65
   at ICSharpCode.ILSpy.TreeNodes.TypeTreeNode.Decompile(Language language, ITextOutput output, DecompilationOptions options) in offset 0
   at ICSharpCode.ILSpy.TextView.DecompilerTextView.DecompileNodes(DecompilationContext context, ITextOutput textOutput) in offset 103
   at ICSharpCode.ILSpy.TextView.DecompilerTextView.<>c__DisplayClass58_0.<DecompileAsync>b__0() in offset 18

Details

• Product in use: ILSpy 9.0 VS extension