Fail on self-decompilation

[greenozon]

Input code

One of the ILSpy dlls failed to decompile
McMaster.Extensions.CommandLineUtils.dll

Erroneous output

Error decompiling for 'McMaster.Extensions.CommandLineUtils.Abstractions\StockValueParsers.cs'
in assembly "C:\IL9\McMaster.Extensions.CommandLineUtils.dll"
 ---> ICSharpCode.ILSpy.AssertionFailedException: 
   at ICSharpCode.ILSpy.ILSpyTraceListener.Fail(String message, String detailMessage) in offset 379
   at System.Diagnostics.TraceInternal.Fail(String message, String detailMessage) in offset 48
   at System.Diagnostics.Debug.Fail(String message, String detailMessage) in offset 0
   at ICSharpCode.Decompiler.CSharp.Transforms.DeclareVariables.ResolveCollisions() in DeclareVariables.cs:line 483
   at ICSharpCode.Decompiler.CSharp.Transforms.DeclareVariables.Analyze(AstNode rootNode) in DeclareVariables.cs:line 173
   at ICSharpCode.Decompiler.CSharp.Transforms.PatternStatementTransform.Run(AstNode rootNode, TransformContext context) in PatternStatementTransform.cs:line 47
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.RunTransforms(AstNode rootNode, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 572
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DecompileTypes(IEnumerable`1 types) in CSharpDecompiler.cs:line 958
   at ICSharpCode.Decompiler.CSharp.ProjectDecompiler.WholeProjectDecompiler.<>c__DisplayClass46_0.<WriteCodeFilesInProject>b__5(IGrouping`2 file) in WholeProjectDecompiler.cs:line 290
-- continuing with outer exception (ICSharpCode.Decompiler.DecompilerException) --
   at ICSharpCode.Decompiler.CSharp.ProjectDecompiler.WholeProjectDecompiler.<>c__DisplayClass46_0.<WriteCodeFilesInProject>b__5(IGrouping`2 file) in WholeProjectDecompiler.cs:line 314
   at System.Threading.Tasks.Parallel.<>c__DisplayClass43_0`2.<PartitionerForEachWorker>b__1(IEnumerator& partitionState, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion) in offset 259
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() in offset 17
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw(Exception source) in offset 0
   at System.Threading.Tasks.Parallel.<>c__DisplayClass43_0`2.<PartitionerForEachWorker>b__1(IEnumerator& partitionState, Int64 timeout, Boolean& replicationDelegateYieldedBeforeCompletion) in offset 609
   at System.Threading.Tasks.TaskReplicator.Replica.Execute() in offset 35

Details

• Product in use:
• ILSpy version 9.0.0.7953+247f161eb35b9159705a92c73c8cf83d0c5e71e4
• .NET version 8.0.11+9cb3b725e3ad2b57ddc9fb2dd48d2d170563a8f5

[siegfriedpammer]

@dgrunwald this is a bug in DeclareVariables. It doesn't properly handle variables in disjunct scopes that have the same name. Not sure, if that is specific to out variables, but in this case the variables involved are out variables.