Bug 9007 - Autocomplete throw ArgumentNullException on ASP.Net ViewPage
Summary: Autocomplete throw ArgumentNullException on ASP.Net ViewPage
Alias: None
Product: Xamarin Studio
Classification: Desktop
Component: Text Editor ()
Version: Trunk
Hardware: PC Linux
: High normal
Target Milestone: ---
Assignee: Mike Krüger
Depends on:
Reported: 2012-12-18 07:29 UTC by ludvichzme
Modified: 2012-12-31 00:17 UTC (History)
1 user (show)

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

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Description ludvichzme 2012-12-18 07:29:37 UTC

Taking this example (ASP.Net MVC View):
<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">

If I just type <% , and then hit ctrl+space to show AutoCompletion, an ArgumentNullException is throwed :
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentNullException: Argument cannot be null.
Parameter name: completionContextProvider

Then, the autocompletion no longer work until I close & reopen the document.

MonoDevelop.CSharp.Completion.CSharpCompletionTextEditorExtension.cs L 228 seems to cause this Exception, since typeSystemSegmentTree is null.

Workaround : add a check before the new CSharpCompletionEngine call :
if (typeSystemSegmentTree == null)
    return null;

I'm gonna do a pull request on the master branch to purpose the patch.

NOTE : It's just prevent the IDE from crashing, but autocompletion doesn't work much.
Comment 1 Mike Krüger 2012-12-31 00:17:29 UTC
fix merged.

(The ASP.NET completion needs a redesign - atm we don't have many resources to fix that properly)