Bug 40373 - Null reference exception in ScrollView
Summary: Null reference exception in ScrollView
Status: VERIFIED FIXED
Alias: None
Product: Xamarin Studio
Classification: Desktop
Component: Shell ()
Version: unspecified
Hardware: PC Mac OS
: Normal normal
Target Milestone: (C8)
Assignee: Marius Ungureanu
URL:
Depends on:
Blocks:
 
Reported: 2016-04-14 02:00 UTC by Alan McGovern
Modified: 2016-07-07 17:59 UTC (History)
4 users (show)

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

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Status:
VERIFIED FIXED

Description Alan McGovern 2016-04-14 02:00:57 UTC
I get this error:
System.NullReferenceException: Object reference not set to an instance of an object
  at MonoDevelop.Ide.Gui.Components.LogView.ShouldAutoScroll () [0x00000] in /Users/alan/Projects/monodevelop/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Gui.Components/LogView.cs:576 
  at MonoDevelop.Ide.Gui.Components.LogView.UnsafeAddText (System.String text, Gtk.TextTag extraTag) [0x00048] in /Users/alan/Projects/monodevelop/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Gui.Components/LogView.cs:590 
  at MonoDevelop.Ide.Gui.Components.LogView+QueuedTextWrite.Execute (MonoDevelop.Ide.Gui.Components.LogView pad) [0x00000] in /Users/alan/Projects/monodevelop/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Gui.Components/LogView.cs:650 
  at MonoDevelop.Ide.Gui.Components.LogView.outputDispatchHandler () [0x00064] in /Users/alan/Projects/monodevelop/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Gui.Components/LogView.cs:481 


in this code:
https://github.com/mono/monodevelop/blob/master/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Gui.Components/LogView.cs#L576

because 'VAdjustment' is null. It happens nearly every time on project load for me. A simple trigger seems to be to open a project which references nugets but they have not been restored.

The error message being logged when it null references is:
"Updating Resources...\n\nThis project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is ../packages/Xamarin.Forms.2.1.0.6524/build/portable-win+net45+wp80+win81+wpa81+MonoAndroid10+MonoTouch10+Xamarin.iOS10/Xamarin.Forms.targets.\n\n"
Comment 2 xamarin-release-manager 2016-04-19 10:37:37 UTC
Fixed in version 6.1.0.662 (master)

Author: therzok
Commit: 1485ad45d544100c4be5d74bfc8ebb2bcb2bde61 (mono/monodevelop)
Comment 4 Alan McGovern 2016-06-29 08:08:07 UTC
It's a race condition - impossible to reliably reproduce
Comment 5 Shruti 2016-07-07 17:59:37 UTC
As per comment 4, this issue is hardly to reproduce. So closing it.

Please reopen If experience this issue again.