Extract Method refactoring fails to capture inputs/outputs when unsafe blocks are included

[Pilchie]

From @AArnott:

using System;

class Program {
    static void Main(string[] args) {
        object value = args;

        // extract from here
        IntPtr p;
        unsafe
        {
            object t = value;
            p = IntPtr.Zero;
        }
        // to here

        Console.WriteLine(p);
    }
}

Open the C# console app in Dev14 and the Program.cs file.
Select lines 7 - 12 and execute the Extract Method command.

Expected
A new method that takes an object as a parameter and returns an IntPtr is created, and an invocation of that method replaces the selected lines that passes in "value" as the parameter and assigns the result to "IntPtr p".

Actual
A method is created that takes no parameters and returns void. Two compile errors are created by the refactoring as a result.

[AArnott]

This repros with unchecked blocks as well.

[gafter]

I suspect this may be a bug in the region analysis APIs. If you discover that is the case, please assign to me and Area-Compilers.

[CyrusNajmabadi]

Yes. this is a bug in the region analysis APIs. Assigning to @gafter

@gafter the core issue is here: We call AnalyzeDataFlow on the pair of statements IntPtr p; and unsafe { }. This fails immediately with a non-successful result. Debugging in a tiny bit, this is because the compiler doesn't get a boundnode for the unsafe { } block. Because there's no end bound node, nothing works.