Moving Log window divider to top while maximized causes rendering errors and UI freeze

[zindy]

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Bug report

This is something I'm noticing in 0.7.0rc1 (both the one you compiled and the one I compile from main).

Describe the bug

Guardrail already in place: If you move the divider between the log list and the details pane all the way to its top allowed position, layout calculation errors occur but are properly handled:

Mar 02, 2026 11:30:40 AM javafx.scene.control.skin.VirtualFlow addTrailingCells
INFO: index exceeds maxCellCount. Check size calculations for class javafx.scene.control.TableRow

However, if the Log window is maximised and the same action is performed, the errors are no longer handled.

The (repeating) error message

```text 11:10:30.522 [JavaFX Application Thread] [INFO ] qupath.lib.gui.QuPathApp - Starting QuPath with parameters: [] Mar 02, 2026 11:10:59 AM javafx.scene.control.skin.VirtualFlow addTrailingCells INFO: index exceeds maxCellCount. Check size calculations for class javafx.scene.control.TableRow Mar 02, 2026 11:11:07 AM javafx.scene.control.skin.VirtualFlow addTrailingCells INFO: index exceeds maxCellCount. Check size calculations for class javafx.scene.control.TableRow Mar 02, 2026 11:11:07 AM javafx.scene.control.skin.VirtualFlow addTrailingCells INFO: index exceeds maxCellCount. Check size calculations for class javafx.scene.control.TableRow java.lang.NullPointerException: Cannot invoke "com.sun.prism.d3d.D3DTextureData.getContext()" because the return value of "com.sun.prism.d3d.D3DTextureResource.getResource()" is null at com.sun.prism.d3d.D3DTexture.getContext(D3DTexture.java:85) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:210) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:154) at com.sun.prism.impl.BaseContext.flushMask(BaseContext.java:115) at com.sun.prism.impl.BaseContext.drawQuads(BaseContext.java:124) at com.sun.prism.impl.VertexBuffer.flush(VertexBuffer.java:98) at com.sun.prism.impl.BaseContext.flushVertexBuffer(BaseContext.java:107) at com.sun.prism.impl.ps.BaseShaderContext.checkState(BaseShaderContext.java:685) at com.sun.prism.impl.ps.BaseShaderContext.validatePaintOp(BaseShaderContext.java:504) at com.sun.prism.impl.ps.BaseShaderContext.validatePaintOp(BaseShaderContext.java:371) at com.sun.prism.impl.ps.BaseShaderGraphics.renderGeneralRoundedPgram(BaseShaderGraphics.java:924) at com.sun.prism.impl.ps.BaseShaderGraphics.renderGeneralRoundedRect(BaseShaderGraphics.java:625) at com.sun.prism.impl.ps.BaseShaderGraphics.fillRect(BaseShaderGraphics.java:1532) at com.sun.javafx.sg.prism.NGRegion.renderBackgroundRectanglesDirectly(NGRegion.java:1112) at com.sun.javafx.sg.prism.NGRegion.renderBackgroundRectangle(NGRegion.java:852) at com.sun.javafx.sg.prism.NGRegion.renderAsRectangle(NGRegion.java:754) at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:575) at com.sun.javafx.sg.prism.CacheFilter.renderNodeToScreen(CacheFilter.java:700) at com.sun.javafx.sg.prism.CacheFilter.render(CacheFilter.java:626) at com.sun.javafx.sg.prism.NGNode.renderCached(NGNode.java:2343) at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2054) at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1955) at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:266) at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:579) at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2063) at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1955) at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:266) at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:579) at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2063) at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1955) at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:266) at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:579) at com.sun.javafx.sg.prism.NGNode.renderForClip(NGNode.java:2279) at com.sun.javafx.sg.prism.NGNode.renderRectClip(NGNode.java:2186) at com.sun.javafx.sg.prism.NGNode.renderClip(NGNode.java:2213) at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2057) at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1955) at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:266) at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:579) at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2063) at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1955) at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:266) at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:579) at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2063) at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1955) at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:266) at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:579) at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2063) at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1955) at com.sun.javafx.tk.quantum.ViewPainter.doPaint(ViewPainter.java:481) at com.sun.javafx.tk.quantum.ViewPainter.paintImpl(ViewPainter.java:321) at com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:92) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source) at com.sun.javafx.tk.RenderJob.run(RenderJob.java:58) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:122) at java.base/java.lang.Thread.run(Unknown Source) java.lang.NullPointerException: Cannot invoke "com.sun.prism.d3d.D3DTextureData.getContext()" because the return value of "com.sun.prism.d3d.D3DTextureResource.getResource()" is null at com.sun.prism.d3d.D3DTexture.getContext(D3DTexture.java:85) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:210) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:154) at com.sun.prism.impl.BaseContext.flushMask(BaseContext.java:115) at com.sun.prism.impl.BaseContext.drawQuads(BaseContext.java:124) at com.sun.prism.impl.VertexBuffer.flush(VertexBuffer.java:98) at com.sun.prism.impl.BaseContext.flushVertexBuffer(BaseContext.java:107) at com.sun.prism.impl.ps.BaseShaderContext.setRenderTarget(BaseShaderContext.java:791) at com.sun.prism.impl.BaseContext.setRenderTarget(BaseContext.java:149) at com.sun.prism.impl.BaseGraphics.(BaseGraphics.java:107) at com.sun.prism.impl.ps.BaseShaderGraphics.(BaseShaderGraphics.java:84) at com.sun.prism.d3d.D3DGraphics.(D3DGraphics.java:40) at com.sun.prism.d3d.D3DGraphics.create(D3DGraphics.java:63) at com.sun.prism.d3d.D3DSwapChain.createGraphics(D3DSwapChain.java:148) at com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:88) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source) at com.sun.javafx.tk.RenderJob.run(RenderJob.java:58) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:122) at java.base/java.lang.Thread.run(Unknown Source) java.lang.NullPointerException: Cannot invoke "com.sun.prism.d3d.D3DTextureData.getContext()" because the return value of "com.sun.prism.d3d.D3DTextureResource.getResource()" is null at com.sun.prism.d3d.D3DTexture.getContext(D3DTexture.java:85) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:210) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:154) at com.sun.prism.impl.BaseContext.flushMask(BaseContext.java:115) at com.sun.prism.impl.BaseContext.drawQuads(BaseContext.java:124) at com.sun.prism.impl.VertexBuffer.flush(VertexBuffer.java:98) at com.sun.prism.impl.BaseContext.flushVertexBuffer(BaseContext.java:107) at com.sun.prism.impl.ps.BaseShaderContext.setRenderTarget(BaseShaderContext.java:791) at com.sun.prism.impl.BaseContext.setRenderTarget(BaseContext.java:149) at com.sun.prism.impl.BaseGraphics.(BaseGraphics.java:107) at com.sun.prism.impl.ps.BaseShaderGraphics.(BaseShaderGraphics.java:84) at com.sun.prism.d3d.D3DGraphics.(D3DGraphics.java:40) at com.sun.prism.d3d.D3DGraphics.create(D3DGraphics.java:63) at com.sun.prism.d3d.D3DSwapChain.createGraphics(D3DSwapChain.java:148) at com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:88) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source) at com.sun.javafx.tk.RenderJob.run(RenderJob.java:58) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:122) at java.base/java.lang.Thread.run(Unknown Source) ```

After the error occurs, the log window becomes completely unresponsive (see screenshot after trying to unmaximise the window and stretching it).

To Reproduce

Steps to reproduce the behavior:

1. Right after opening 0.7.0rc1, press Ctrl-Shift-L
2. Maximise the log window (win + up arrow)
3. move the divider towards the log entries.
4. See error messages pasted above

Screenshots

Desktop (please complete the following information):

• OS: Windows 10
• QuPath Version: 0.7.0rc1, and snapshot compiled from main.

[petebankhead]

I couldn't replicate this on a Windows 10 laptop (nor on a Mac). I was using a build from the current main.

Could there be something else different in your setup, e.g., a second monitor? Are you able to try a different computer to see if it happens for you there?

And am I right to think it didn't happen with v0.6.0?

[zindy]

You're absolutely right, That was an important clue I missed. I have to maximise the log window on a secondary screen for the bug to occur. The secondary screen can be portrait or landscape, the bug occurs regardless. The bug does not occur if I maximise the Log window on the main screen (whether there is a secondary screen attached or not).

Win 11 error message (v0.7.0-rc1)

```text java.lang.NullPointerException: Cannot invoke "com.sun.prism.d3d.D3DTextureData.getContext()" because the return value of "com.sun.prism.d3d.D3DTextureResource.getResource()" is null at com.sun.prism.d3d.D3DTexture.getContext(D3DTexture.java:85) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:210) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:154) at com.sun.prism.impl.BaseContext.flushMask(BaseContext.java:115) at com.sun.prism.impl.BaseContext.drawQuads(BaseContext.java:124) at com.sun.prism.impl.VertexBuffer.flush(VertexBuffer.java:98) at com.sun.prism.impl.BaseContext.flushVertexBuffer(BaseContext.java:107) at com.sun.prism.impl.ps.BaseShaderContext.setRenderTarget(BaseShaderContext.java:791) at com.sun.prism.impl.BaseContext.setRenderTarget(BaseContext.java:149) at com.sun.prism.impl.BaseGraphics.(BaseGraphics.java:107) at com.sun.prism.impl.ps.BaseShaderGraphics.(BaseShaderGraphics.java:84) at com.sun.prism.d3d.D3DGraphics.(D3DGraphics.java:40) at com.sun.prism.d3d.D3DGraphics.create(D3DGraphics.java:63) at com.sun.prism.d3d.D3DRTTexture.createGraphics(D3DRTTexture.java:80) at com.sun.prism.d3d.D3DResourceFactory.createRTTexture(D3DResourceFactory.java:360) at com.sun.prism.d3d.D3DResourceFactory.createPresentable(D3DResourceFactory.java:379) at com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:81) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source) at com.sun.javafx.tk.RenderJob.run(RenderJob.java:58) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:122) at java.base/java.lang.Thread.run(Unknown Source) java.lang.NullPointerException: Cannot invoke "com.sun.prism.d3d.D3DTextureData.getContext()" because the return value of "com.sun.prism.d3d.D3DTextureResource.getResource()" is null at com.sun.prism.d3d.D3DTexture.getContext(D3DTexture.java:85) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:210) at com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:154) at com.sun.prism.impl.BaseContext.flushMask(BaseContext.java:115) at com.sun.prism.impl.BaseContext.drawQuads(BaseContext.java:124) at com.sun.prism.impl.VertexBuffer.flush(VertexBuffer.java:98) at com.sun.prism.impl.BaseContext.flushVertexBuffer(BaseContext.java:107) at com.sun.prism.impl.ps.BaseShaderContext.setRenderTarget(BaseShaderContext.java:791) at com.sun.prism.impl.BaseContext.setRenderTarget(BaseContext.java:149) at com.sun.prism.impl.BaseGraphics.(BaseGraphics.java:107) at com.sun.prism.impl.ps.BaseShaderGraphics.(BaseShaderGraphics.java:84) at com.sun.prism.d3d.D3DGraphics.(D3DGraphics.java:40) at com.sun.prism.d3d.D3DGraphics.create(D3DGraphics.java:63) at com.sun.prism.d3d.D3DRTTexture.createGraphics(D3DRTTexture.java:80) at com.sun.prism.d3d.D3DResourceFactory.createRTTexture(D3DResourceFactory.java:360) at com.sun.prism.d3d.D3DResourceFactory.createPresentable(D3DResourceFactory.java:379) at com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:81) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source) at com.sun.javafx.tk.RenderJob.run(RenderJob.java:58) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:122) at java.base/java.lang.Thread.run(Unknown Source) ```

Is v0.7.0 the only version affected? No, on the same machine (win11 laptop with secondary screen attached), I can confirm this was already an issue in QuPath v0.6.0:

Cheers,
Egor

[petebankhead]

Ah good, thanks for checking.

I connected an external monitor and still couldn't replicate it (this time Windows 10 and v0.6.0).

It sounds like it could be a bug in JavaFX - similar exceptions have been reported (e.g., here and here).

The second suggests that maybe the issue is related to screen size rather than whether it's a secondary monitor...? My monitor is rather small.

I don't know if it's possible to work around this in QuPath. If it is, it will probably require a change to https://github.com/qupath/log-viewer - although I'm not sure what could be done.

One thing you might check is if you clone the code from that repo, you can use ./gradlew run to launch a log viewer completely independent from QuPath. If that still has a problem, then I'd transfer this issue to that repo.

[zindy]

On my main machine (Win10), I have 3 4K monitors:

If I maximise your standalone log viewer on 1 and move the divider all the way to the top, I can't make it crash. But, if I try the same procedure on monitor 2 or 3, then it does.

java.lang.NullPointerException: Cannot invoke "com.sun.prism.d3d.D3DTextureData.getContext()" because the return value of "com.sun.prism.d3d.D3DTextureResource.getResource()" is null
        at javafx.graphics@25/com.sun.prism.d3d.D3DTexture.getContext(D3DTexture.java:85)
        at javafx.graphics@25/com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:210)
        at javafx.graphics@25/com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:154)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.flushMask(BaseContext.java:115)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.drawQuads(BaseContext.java:124)
        at javafx.graphics@25/com.sun.prism.impl.VertexBuffer.flush(VertexBuffer.java:98)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.flushVertexBuffer(BaseContext.java:107)
        at javafx.graphics@25/com.sun.prism.impl.ps.BaseShaderContext.setRenderTarget(BaseShaderContext.java:789)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.setRenderTarget(BaseContext.java:149)
        at javafx.graphics@25/com.sun.prism.impl.BaseGraphics.<init>(BaseGraphics.java:107)
        at javafx.graphics@25/com.sun.prism.impl.ps.BaseShaderGraphics.<init>(BaseShaderGraphics.java:84)
        at javafx.graphics@25/com.sun.prism.d3d.D3DGraphics.<init>(D3DGraphics.java:40)
        at javafx.graphics@25/com.sun.prism.d3d.D3DGraphics.create(D3DGraphics.java:63)
        at javafx.graphics@25/com.sun.prism.d3d.D3DRTTexture.createGraphics(D3DRTTexture.java:80)
        at javafx.graphics@25/com.sun.prism.d3d.D3DResourceFactory.createRTTexture(D3DResourceFactory.java:360)
        at javafx.graphics@25/com.sun.prism.d3d.D3DResourceFactory.createPresentable(D3DResourceFactory.java:379)
        at javafx.graphics@25/com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:81)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:545)
        at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:369)
        at javafx.graphics@25/com.sun.javafx.tk.RenderJob.run(RenderJob.java:58)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1090)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:614)
        at javafx.graphics@25/com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:122)
        at java.base/java.lang.Thread.run(Thread.java:1474)
java.lang.NullPointerException: Cannot invoke "com.sun.prism.d3d.D3DTextureData.getContext()" because the return value of "com.sun.prism.d3d.D3DTextureResource.getResource()" is null
        at javafx.graphics@25/com.sun.prism.d3d.D3DTexture.getContext(D3DTexture.java:85)
        at javafx.graphics@25/com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:210)
        at javafx.graphics@25/com.sun.prism.d3d.D3DTexture.update(D3DTexture.java:154)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.flushMask(BaseContext.java:115)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.drawQuads(BaseContext.java:124)
        at javafx.graphics@25/com.sun.prism.impl.VertexBuffer.flush(VertexBuffer.java:98)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.flushVertexBuffer(BaseContext.java:107)
        at javafx.graphics@25/com.sun.prism.impl.ps.BaseShaderContext.setRenderTarget(BaseShaderContext.java:789)
        at javafx.graphics@25/com.sun.prism.impl.BaseContext.setRenderTarget(BaseContext.java:149)
        at javafx.graphics@25/com.sun.prism.impl.BaseGraphics.<init>(BaseGraphics.java:107)
        at javafx.graphics@25/com.sun.prism.impl.ps.BaseShaderGraphics.<init>(BaseShaderGraphics.java:84)
        at javafx.graphics@25/com.sun.prism.d3d.D3DGraphics.<init>(D3DGraphics.java:40)
        at javafx.graphics@25/com.sun.prism.d3d.D3DGraphics.create(D3DGraphics.java:63)
        at javafx.graphics@25/com.sun.prism.d3d.D3DRTTexture.createGraphics(D3DRTTexture.java:80)
        at javafx.graphics@25/com.sun.prism.d3d.D3DResourceFactory.createRTTexture(D3DResourceFactory.java:360)
        at javafx.graphics@25/com.sun.prism.d3d.D3DResourceFactory.createPresentable(D3DResourceFactory.java:379)
        at javafx.graphics@25/com.sun.javafx.tk.quantum.PresentingPainter.run(PresentingPainter.java:81)
        at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:545)
        at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:369)
        at javafx.graphics@25/com.sun.javafx.tk.RenderJob.run(RenderJob.java:58)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1090)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:614)
        at javafx.graphics@25/com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:122)
        at java.base/java.lang.Thread.run(Thread.java:1474)

I'll check at my end, don't spend time on this Pete, sorry!

Kind regards,
Egor

[zindy]

Ah! Gemini suggested changing the TableView minHeight from -Infinity to 100.0

                 <TableView fx:id="tableViewLog" minHeight="100.0" minWidth="-Infinity" prefHeight="10.0" prefWidth="10.0" styleClass="log-table" tableMenuButtonVisible="true">

in "log-viewer\logviewer-ui-main\src\main\resources\qupath\ui\logviewer\ui\main\log-viewer.fxml"

and this has prevented your log viewer from crashing with the procedure detailed above.

Until you have time and brain power to give to this, I'm fine with "not moving the divider all the way to the top" for now.

Kind regards,
Egor

[Rylern]

We weren't able to reproduce the issue, but your fix was implemented on #79. If it's fine with you, we can merge the PR and close this issue.