Fix initialization of FakeProperty with setter

[exyi]

ILSpy crashed with NullReferenceException when it couldn't resolve some dependency (Newtonsoft.Json in my case, the problem was around JObject.Item[string] indexer)

Seems like a typo when FakeProperty is initialized - the setter method was assigned to the Getter property

Solution

First commit contains the actual fix.

In the second commit I included some asserts and a ToString implementation I used to debug the problem. I'm guessing that more asserts would be welcome, but if you don't like it, just merge only the first commit.

• At least one test covering the code changed
  • Sorry, but I couldn't make the tests run on Linux, is there any way?
  • I also don't know how to replicate this problem in unit tests - I'd have to compile a dll against some library which the decompiler won't see at runtime.

[siegfriedpammer]

• I also don't know how to replicate this problem in unit tests - I'd have to compile a dll against some library which the decompiler won't see at runtime.

You could create an IL-Pretty-Test like this one: https://github.com/icsharpcode/ILSpy/blob/master/ICSharpCode.Decompiler.Tests/TestCases/ILPretty/UnknownTypes.il

ILAsm will happily assemble a file that contains references to unknown types/members.

[exyi]

I added a test case which I believe covers the changed code.

I also needed to slightly change output of one the existing test. It does not change the meaning of the code, but it's now eager to merge assignments into var v = (x.Prop=c.Prop) expression and then it does not know how to name the variable v.

[siegfriedpammer]

Thank you for your contribution!