Thin horizontal lines appear between lines of text at some positions when scrolling vertically

[swpalmer]

Expected Behavior

There should be no visible gaps between lines of text.

Actual Behavior

When scrolling vertically think horizontal lines appear between the lines of text. Some scroll positions are worse than others, so have no lines. IT appears to be a single pixel or less, depending on the scroll position.

Reproducible Demo

CoreArea with a stylesheet that sets the line background to a dark color makes it easier to see.

See attached screenshots, taken from the same program with slightly different scroll positions.

Environment info:

• RichTextFX Version: 0.10.7
• Operating System: macOS 12.2.1
• Java version: 17.0.2 (Zulu build from Azul that includes JavaFX)

[Jugen]

This is a bug in the Flowless library that RichTextFX uses.