Bug 29517 - TryUpdate for ConcurrentDictionary behaves differently from .NET when comparison value is null
Summary: TryUpdate for ConcurrentDictionary behaves differently from .NET when compari...
Status: RESOLVED FIXED
Alias: None
Product: Class Libraries
Classification: Mono
Component: System ()
Version: 3.10.0
Hardware: PC Linux
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
URL:
Depends on:
Blocks:
 
Reported: 2015-04-29 04:45 UTC by Narinder
Modified: 2015-04-29 09:13 UTC (History)
2 users (show)

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

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Status:
RESOLVED FIXED

Description Narinder 2015-04-29 04:45:38 UTC
The following piece of code :

        static void Main(string[] args)
        {
            try
            {
                ConcurrentDictionary<string, string> theDict = new ConcurrentDictionary<string, string>();

                string nullString = null;
                theDict.GetOrAdd("key", nullString);
                theDict.TryUpdate("key", "hello", null);

            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }

Throws an exception on Mono :
Object reference not set to an instance of an object

on .NET 4.0 no exception is thrown.

Mono Setup is :
Mono JIT compiler version 3.10.0 ((no/633e444 Wed Nov 12 15:36:54 GMT 2014)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           __thread
	SIGSEGV:       altstack
	Notifications: epoll
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug 
	LLVM:          supported, not enabled.
	GC:            sgen

On Debian
Comment 1 Marek Safar 2015-04-29 07:05:29 UTC
Fixed in Mono 4.0
Comment 2 Narinder 2015-04-29 09:13:20 UTC
Thanks !