System.Drawing.Common tests failed on Windows Mono due to COM wrappers

[akoeplinger]

After #54884 these tests started failing on Mono on Windows:

• ToBitmap_PngIconSupportedInSwitches_Success
• ToBitmap_PngIconNotSupportedInSwitches_ThrowsArgumentOutOfRangeException
• Ctor_IntPtrZeroIV_ThrowsArgumentException
• Ctor_InvalidFrameUnitIII_ThrowsArgumentException
• Ctor_InvalidEmfTypeIII_ThrowsArgumentException

Probably something to do with Mono not supporting COM on Windows: #39704 (comment)

Example stacktrace:

  System.TypeInitializationException: The type initializer for 'System.Drawing.DrawingCom' threw an exception.
 ---> System.PlatformNotSupportedException: Operation is not supported on this platform.
   at System.Drawing.DrawingCom.InitializeComInterfaceEntry() in /_/src/libraries/System.Drawing.Common/src/System/Drawing/DrawingCom.COMWrappers.cs:line 30
   at System.Drawing.DrawingCom..cctor() in /_/src/libraries/System.Drawing.Common/src/System/Drawing/DrawingCom.COMWrappers.cs:line 22
   --- End of inner exception stack trace ---
   at System.Drawing.Image.Save(Stream stream, ImageCodecInfo encoder, EncoderParameters encoderParams) in /_/src/libraries/System.Drawing.Common/src/System/Drawing/Image.Windows.cs:line 248
   at System.Drawing.Image.Save(Stream stream, ImageFormat format) in /_/src/libraries/System.Drawing.Common/src/System/Drawing/Image.Windows.cs:line 210
   at System.Drawing.Tests.IconTests.GetPngIcon() in /_/src/libraries/System.Drawing.Common/tests/IconTests.cs:line 685
   at System.Drawing.Tests.IconTests.<ToBitmap_PngIconSupportedInSwitches_Success>g__VerifyPng|44_0() in /_/src/libraries/System.Drawing.Common/tests/IconTests.cs:line 618
   at System.Drawing.Tests.IconTests.<>c.<ToBitmap_PngIconSupportedInSwitches_Success>b__44_1() in /_/src/libraries/System.Drawing.Common/tests/IconTests.cs:line 640
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) in /_/src/mono/System.Private.CoreLib/src/System/Reflection/RuntimeMethodInfo.cs:line 370

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Issue Details

---

After #54884 these tests started failing on Mono on Windows:

• ToBitmap_PngIconSupportedInSwitches_Success
• ToBitmap_PngIconNotSupportedInSwitches_ThrowsArgumentOutOfRangeException
• Ctor_IntPtrZeroIV_ThrowsArgumentException
• Ctor_InvalidFrameUnitIII_ThrowsArgumentException
• Ctor_InvalidEmfTypeIII_ThrowsArgumentException

Example stacktrace:

  System.TypeInitializationException: The type initializer for 'System.Drawing.DrawingCom' threw an exception.
 ---> System.PlatformNotSupportedException: Operation is not supported on this platform.
   at System.Drawing.DrawingCom.InitializeComInterfaceEntry() in /_/src/libraries/System.Drawing.Common/src/System/Drawing/DrawingCom.COMWrappers.cs:line 30
   at System.Drawing.DrawingCom..cctor() in /_/src/libraries/System.Drawing.Common/src/System/Drawing/DrawingCom.COMWrappers.cs:line 22
   --- End of inner exception stack trace ---
   at System.Drawing.Image.Save(Stream stream, ImageCodecInfo encoder, EncoderParameters encoderParams) in /_/src/libraries/System.Drawing.Common/src/System/Drawing/Image.Windows.cs:line 248
   at System.Drawing.Image.Save(Stream stream, ImageFormat format) in /_/src/libraries/System.Drawing.Common/src/System/Drawing/Image.Windows.cs:line 210
   at System.Drawing.Tests.IconTests.GetPngIcon() in /_/src/libraries/System.Drawing.Common/tests/IconTests.cs:line 685
   at System.Drawing.Tests.IconTests.<ToBitmap_PngIconSupportedInSwitches_Success>g__VerifyPng|44_0() in /_/src/libraries/System.Drawing.Common/tests/IconTests.cs:line 618
   at System.Drawing.Tests.IconTests.<>c.<ToBitmap_PngIconSupportedInSwitches_Success>b__44_1() in /_/src/libraries/System.Drawing.Common/tests/IconTests.cs:line 640
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) in /_/src/mono/System.Private.CoreLib/src/System/Reflection/RuntimeMethodInfo.cs:line 370

Probably something to do with not supporting COM on Mono on Windows: #39704 (comment)

Author:	akoeplinger
Assignees:	-
Labels:	area-VM-meta-mono, os-windows
Milestone:	7.0.0

[danmoseley]

@safern do we support System.Drawing on Mono Windows at all? I assume not -- the whole test library should not run in that config.

[safern]

That's a good question, but actually we do 😄

[danmoseley]

Ah I see, we only use COM for a few things - Bitmaps, Images, Metafiles? In that case, unless we think the message is bad, this issue can be closed as by design.

[safern]

This was caused because we needed to use COMWrappers on 6.0 to make it trimmable safe. However it seems like Mono doesn't support COMWrappers? And yeah, the COMWrappers are mostly used to read Images from streams as we need to use an IStream com interface because that is what GDI+ uses.

Perhaps we could condition the code to use the legacy COM if running on Mono?

cc: @eerhardt

[eerhardt]

I was under the impression that Mono didn't support COM at all.

Perhaps we could condition the code to use the legacy COM if running on Mono?

Is that worth it? What are the scenarios where customers will run with Mono on Windows?

COMWrappers are the way forward. If we believe "Mono on Windows" is important, then Mono needs to support COMWrappers. We are going to be converting more and more COM usage over to COMWrappers, so this will just crop up in more places.

cc @jkotas @AaronRobinsonMSFT

[jkotas]

We do not have official support for Mono on Windows.