A field and property that differ only by case of a type with the same name triggers an internal compiler error

[nerdzero]

MonoDevelop recently made this change:  https://github.com/mono/monodevelop/commit/f57fbcd49275c4f99ee11e12f5b17e3937a573ee#L3R711

It adds a field called "diffTracker" of type "DiffTracker?" and a property called "DiffTracker?" also of type "DiffTracker?". This triggers a duplicate key exception in Container.addDecl when reading the MonoDevelop library.

This prevents compilation of the Cobra addin for MD/XS. Sad face.

Here's part of the stack trace:

Unhandled Exception:
System.ArgumentException: An element with the same key already exists in the dictionary.
  at System.Collections.Generic.Dictionary`2[TKey,TValue].Add (System.Collections.Generic.TKey key, System.Collections.Generic.TValue value) [0x00000] in <filename unknown>:0 
  at Container`1[IBoxMember].AddDecl (IBoxMember decl) [0x00000] in <filename unknown>:0 
  at Box._scanClrProperties () [0x00000] in <filename unknown>:0 
  at Class.ScanNativeTypeClr () [0x00000] in <filename unknown>:0 
  at ClrBackEnd.ScanNativeType (Box box) [0x00000] in <filename unknown>:0 
  at Box._scanNativeType () [0x00000] in <filename unknown>:0 
  at Box._bindInh () [0x00000] in <filename unknown>:0 
  at ClassOrStruct._bindInh () [0x00000] in <filename unknown>:0 
  at Node.BindInh () [0x00000] in <filename unknown>:0 
  at Box.BindInh () [0x00000] in <filename unknown>:0 
  at Box.__prepLibraryInh () [0x00000] in <filename unknown>:0 
  at Box._prepLibraryInh () [0x00000] in <filename unknown>:0 
  at Box._prepLibraryBox () [0x00000] in <filename unknown>:0 
  at Box.PrepIfNeeded () [0x00000] in <filename unknown>:0 
  at Box.__memberForName (System.String name) [0x00000] in <filename unknown>:0 
  at Box.__memberForNameIncludingExtensions (System.String name) [0x00000] in <filename unknown>:0 
  at Box.MemberForName (System.String name) [0x00000] in <filename unknown>:0 
  at Class.MemberForName (System.String name) [0x00000] in <filename unknown>:0 
  at NameExpr.MemberForName (System.String name) [0x00000] in <filename unknown>:0 
  at CallExpr._bindImp () [0x00000] in <filename unknown>:0 
  at Node.BindImp () [0x00000] in <filename unknown>:0 
  at Stmt.BindImp () [0x00000] in <filename unknown>:0
  ...

[Charles]

I'll take a look.

[Charles]

I tried to recreate this like so:

// Lib.cs
using System;

namespace Lib {
	
	public class Foo {
	
		protected int bar;
	
		public int Bar {
			get { return bar; }
			set { bar = value; }
		}

	}

}

mcs -t:library Lib.cs

use Lib

class P

    def main
        trace Foo
        f = Foo()
        trace f.bar
        f.bar = 2
        assert f.bar == 2
        trace f.bar
        print 'done.'

And it works fine:

    trace : Foo=Lib.Foo (MonoType)
          - at use-lib.cobra:7
          - in P.main

    trace : f.bar=0
          - at use-lib.cobra:9
          - in P.main

    trace : f.bar=2
          - at use-lib.cobra:12
          - in P.main
done.

Could it be something else?

[Charles]

Nevermind. Got it. Both members have to be public.

[Charles]

Fixed. Running tests.

[Charles]

Fixed in changeset:3020