Assertion fails after pinned region detection in System.Data.dll

[siegfriedpammer]

Input code

C:\WINDOWS\Microsoft.NET\assembly\GAC_32\System.Data\v4.0_4.0.0.0__b77a5c561934e089\System.Data.dll
@0600009C ADALNativeWrapper.ADALGetAccessToken

Erroneous output

ICSharpCode.ILSpy.AssertionFailedException: Container should not have any unreachable blocks
   at ICSharpCode.ILSpy.ILSpyTraceListener.Fail(String message, String detailMessage) in ILSpyTraceListener.cs:line 82
   at ICSharpCode.ILSpy.ILSpyTraceListener.Fail(String message) in ILSpyTraceListener.cs:line 47
   at System.Diagnostics.TraceInternal.Fail(String message) in offset 55
   at System.Diagnostics.Debug.Assert(Boolean condition, String message) in offset 7
   at ICSharpCode.Decompiler.IL.BlockContainer.CheckInvariant(ILPhase phase) in BlockContainer.cs:line 187
   at ICSharpCode.Decompiler.IL.ILInstruction.CheckInvariant(ILPhase phase) in ILInstruction.cs:line 79
   at ICSharpCode.Decompiler.IL.ILFunction.CheckInvariant(ILPhase phase) in ILFunction.cs:line 252
   at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DecompileBody(IMethod method, EntityDeclaration entityDecl, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1329

Expected output

no assertion

Details

• Product in use: ILSpy
• Version in use: master
• Occurs after pinned region detection

[dgrunwald]

This is C++/CLI code. C++/CLI pinned_ptr really doesn't map cleanly to C# fixed statements :(
Block IL_00b8 pins the contents of a string. There is no unpin instruction (the pin is valid for the remainder of the function).
Note how IL_00b8 can be bypassed via the IL_00a0->IL_00c5 edge; so it's unclear whether the remainder of the function should be inside or outside the fixed statement.

[dgrunwald]

The assertion refers to IL_00c3 which apparently gets clones into the pinned region when it should be moved into it because it's not reachable from outside the pinned region.