[Linux] System.Drawing.Common not working on Linux

[djthegr8]

Description

When using System.Drawing.Common, I am getting a DLL error with user32.dll as an import on Linux.

Configuration

• Which version of .NET is the code running on? 5.0.2
• What OS and version, and what distro if applicable? Ubuntu 20.04 Focal Fossa
• What is the architecture (x64, x86, ARM, ARM64)? x64
• Do you know whether it is specific to that configuration? No

Regression?

Not really, but it works in Windows

Other information

[ghost]

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Issue Details

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Description

When using System.Drawing.Common, I am getting a DLL error with user32.dll as an import on Linux.

Configuration

• Which version of .NET is the code running on? 5.0.2
• What OS and version, and what distro if applicable? Ubuntu 20.04 Focal Fossa
• What is the architecture (x64, x86, ARM, ARM64)? x64
• Do you know whether it is specific to that configuration? No

Regression?

Not really, but it works in Windows

Other information

Author:	djthegr8
Assignees:	-
Labels:	area-System.Drawing, untriaged
Milestone:	-

[djthegr8]

Update: It only happens for some specific data, and works otherwise

[safern]

@djthegr8 thank you for the report. Would you mind sharing a simple repro so that I can test it out and see what is the issue?

[djthegr8]

Because it is current a part of a modestly large project, it would take some time to reproduce, will try to send it as soon as possible

[jkotas]

@safern The problem is pretty obvious by looking at the code. We have PInvokes of Windows GetSystemMetrics API in Unix binary. The problem is triggered when FillPie fails for some reason. You should be able to simulate it by changing FillPie to fail.

[safern]

I see makes sense. It should fail with more than just FillPie. It seems like the call to GetSystemMetrics is trying to figure out if we are in a terminal server session that is remotely controlled. I think we can check if we are running on Windows before calling GetSystemMetrics.

[jkotas]

System.Drawing.Common has separate builds for Windows vs. Unix, so it would be best to just not include the Windows PInvokes in the Unix builds.

[djthegr8]

Besides, could I get a better error because I don't know why FillPie should fail

[djthegr8]

@safern correct me if I am wrong, but would the PR prevent this error and allow my code to run, or would it throw a different error?

[jkotas]

@djthegr8 Yes, this change won't prevent the error. It will produce a better error message that should give you a better idea why FillPie is failing.

[djthegr8]

Fair enough I guess, at least I would be able to debug and fix

…

On Wed, 10 Mar 2021, 17:57 Jan Kotas, ***@***.***> wrote: @djthegr8 <https://github.com/djthegr8> Yes, this change won't prevent the error. It will produce a better error message that should give you a better idea why FillPie is failing. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#49275 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AKQZA76U3QJB5D7OC4F7BPDTC5JSLANCNFSM4YXXFIWA> .

[djthegr8]

@safern apologies for bothering you, but could you tell me how could I use the library with the PR? Thanks.