DrawLines_PointFs, DrawBezier_PointFs, DrawBezier_Points and DrawLines_Points failing sporadically in CI

[stephentoub]

I've seen these fail multiple times in CI now, e.g.
https://mc.dot.net/#/user/dotnet-maestro-bot/pr~2Fjenkins~2Fdotnet~2Fcorefx~2Fmaster~2F/test~2Ffunctional~2Fcli~2F/7868028f16d0fb97037930838ec20cba5077191f/workItem/System.Drawing.Common.Tests/wilogs

2018-06-26 22:47:39,723: INFO: proc(54): run_and_log_output: Output:    System.Drawing.Tests.Graphics_DrawBezierTests.DrawBezier_PointFs [FAIL]
2018-06-26 22:47:39,723: INFO: proc(54): run_and_log_output: Output:       Assert.Equal() Failure
2018-06-26 22:47:39,723: INFO: proc(54): run_and_log_output: Output:       Expected: Byte[] [208, 0, 8, 33, 6, ...]
2018-06-26 22:47:39,723: INFO: proc(54): run_and_log_output: Output:       Actual:   Byte[] [27, 206, 219, 21, 255, ...]
2018-06-26 22:47:39,737: INFO: proc(54): run_and_log_output: Output:       Stack Trace:
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:          D:\j\workspace\windows-TGrou---f8ac6754\src\System.Drawing.Common\tests\DrawingTest.cs(21,0): at System.Drawing.Tests.DrawingTest.ValidateImageContent(Image image, Byte[] expectedHash)
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:          D:\j\workspace\windows-TGrou---f8ac6754\src\System.Drawing.Common\tests\Graphics_DrawBezierTests.cs(59,0): at System.Drawing.Tests.Graphics_DrawBezierTests.DrawBezier_PointFs()
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:    System.Drawing.Tests.Graphics_DrawLineTests.DrawLines_PointFs [FAIL]
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:       Assert.Equal() Failure
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:       Expected: Byte[] [142, 194, 251, 180, 222, ...]
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:       Actual:   Byte[] [89, 188, 96, 22, 200, ...]
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:       Stack Trace:
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:          D:\j\workspace\windows-TGrou---f8ac6754\src\System.Drawing.Common\tests\DrawingTest.cs(21,0): at System.Drawing.Tests.DrawingTest.ValidateImageContent(Image image, Byte[] expectedHash)
2018-06-26 22:47:39,987: INFO: proc(54): run_and_log_output: Output:          D:\j\workspace\windows-TGrou---f8ac6754\src\System.Drawing.Common\tests\Graphics_DrawLineTests.cs(32,0): at System.Drawing.Tests.Graphics_DrawLineTests.DrawLines_PointFs()

I could be wrong, but I believe I only started seeing it after dotnet/corefx#30099.
cc: @safern, @JeremyKuhne

[JeremyKuhne]

We can disable these pending further investigation. I assumed that drawing wouldn't change, but I'm likely missing some key environmental input.

[safern]

I've opened: dotnet/corefx#30684 to disable.

@JeremyKuhne I've assigned the issue to you so that you can investigate what changed.

Fyi: @eerhardt

[jkotas]

Failed on dotnet/coreclr#20532

[jkotas]

Failed in dotnet/runtime#52918

[adamsitnik]

Failed in dotnet/runtime#52720

C:\h\w\AFB90990\w\A0EE0925\e>xunit.console.exe System.Drawing.Common.Tests.dll -xml testResults.xml -nologo -nocolor -notrait category=IgnoreForCI -notrait category=OuterLoop -notrait category=failing  
  Discovering: System.Drawing.Common.Tests (app domain = on [no shadow copy], method display = ClassAndMethod, method display options = None)
  Discovered:  System.Drawing.Common.Tests (found 1999 of 2047 test cases)
  Starting:    System.Drawing.Common.Tests (parallel test collections = on, max threads = 2)
    System.Drawing.Tests.ImageAnimatorManualTests.AnimateAndCaptureFrames [SKIP]
      Condition(s) not met: "ManualTestsEnabled"
    System.Drawing.Tests.Graphics_DrawBezierTests.DrawBezier_PointFs [FAIL]
      Assert.Equal() Failure
      Expected: Byte[] [208, 0, 8, 33, 6, ...]
      Actual:   Byte[] [79, 110, 253, 57, 153, ...]
      Stack Trace:
        /_/src/libraries/System.Drawing.Common/tests/DrawingTest.cs(21,0): at System.Drawing.Tests.DrawingTest.ValidateImageContent(Image image, Byte[] expectedHash)
        /_/src/libraries/System.Drawing.Common/tests/Graphics_DrawBezierTests.cs(63,0): at System.Drawing.Tests.Graphics_DrawBezierTests.DrawBezier_PointFs()
    System.Drawing.Tests.Graphics_DrawLineTests.DrawLines_PointFs [FAIL]
      Assert.Equal() Failure
      Expected: Byte[] [142, 194, 251, 180, 222, ...]
      Actual:   Byte[] [79, 110, 253, 57, 153, ...]
      Stack Trace:
        /_/src/libraries/System.Drawing.Common/tests/DrawingTest.cs(21,0): at System.Drawing.Tests.DrawingTest.ValidateImageContent(Image image, Byte[] expectedHash)
        /_/src/libraries/System.Drawing.Common/tests/Graphics_DrawLineTests.cs(35,0): at System.Drawing.Tests.Graphics_DrawLineTests.DrawLines_PointFs()

[JeremyKuhne]

Changing these tests to validate the lockbits, which should be more stable.