Bug 3344 - [newresolver] editor crashes on completion in the middle of foreach (after "in ")
Summary: [newresolver] editor crashes on completion in the middle of foreach (after "i...
Alias: None
Product: Xamarin Studio
Classification: Desktop
Component: C# Binding ()
Version: Trunk
Hardware: PC Windows
: --- major
Target Milestone: ---
Assignee: Mike Krüger
Depends on:
Reported: 2012-02-10 00:50 UTC by Atsushi Eno
Modified: 2012-02-10 03:13 UTC (History)
1 user (show)

Is this bug a regression?: ---
Last known good build:

the patch to my project (see description) (2.35 KB, application/octet-stream)
2012-02-10 00:50 UTC, Atsushi Eno
sshot for the crasher error. (85.08 KB, image/png)
2012-02-10 00:50 UTC, Atsushi Eno

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Description Atsushi Eno 2012-02-10 00:50:07 UTC
Created attachment 1339 [details]
the patch to my project (see description)

(This is not going to be a great bug report without minimized test case, but it's still *sort of* reproducibe so I think this could still be of sort of help. If I got a chance to drill down and get a smaller case, I'll post updates.)

I'm trying some complicated code from my mono-reactive project and somehow found a crasher. It is reproducible by the following steps, but likely only when the code completion DB is *not* finished.

- git clone git://github.com/atsushieno/mono-reactive.git
- checkout cb742c3a
- apply the attached patch.
- Open mono-reactive.sln
- Open System.Reactive.Linq/Observable.cs
- go to line 1100, which is:  foreach (var r in rsub.OnNext (v);
- Delete "in " and retype it ("in ")
- MD crashes, with an error window I'm going to attach sshot next.

This also happens when I enter a new "foreach (var r in " within the delegate that begins with line 1080. (Though copy-pasting something next to "in" did not crash. The whitespace has to be entered manually to reproduce it.)
Comment 1 Atsushi Eno 2012-02-10 00:50:49 UTC
Created attachment 1340 [details]
sshot for the crasher error.
Comment 2 Atsushi Eno 2012-02-10 01:24:32 UTC
I could trim down the repro significantly. Enter "in " after "foreach (var r" at line 18 below:

using System;
using System.Collections.Generic;

namespace MyApp
	public interface ISubject<T>
	public class Test<T,TRight,TLeft>
		public void Foo (IObserver<T> observer)
			var rightSubs = new List<ISubject<TRight>> ();
			var rightVals = new List<TRight> ();
			Observer.Create<TLeft> (v => {
				ISubject<TRight> rsub = new ReplaySubject<TRight> ();
				foreach (var r 
			}, () => sub.OnCompleted ());
Comment 3 Mike Krüger 2012-02-10 03:13:16 UTC
No wasn't a crash - was only a failed assertion. Since the resolver is now really lazy it does things twice sometimes.

I fixed the assertion.