TextMate syntax coloring doesn't appear on first toggle split editor

[sdaimwood]

Our organization maintains several language servers that use TM4E in an eclipse-based product. We've had customer reports and verified that when first using the Toggle Split Editor view, the newly opened window does not highlight until it is toggled on a second time.

Using the publicly available YAML editor as an example:

1. Open YAML source in the YAML Editor with Window/Editor/Toggle
   Split Editor (Vertical).
   The new second window will have no syntax highlighting.

2. Without closing, use same YAML source with Window/Editor/Toggle Split Editor
   (Horizontal).
   The new horizontally split window does have syntax highlighting.

3. Use same YAML source with Window/Editor/Toggle Split Editor
   (Vertical).
   The new vertically split screen will have syntax highlighting.

It appears that for each file, only the first invocation of split screen editing doesn't have highlighting, but every following invocation does.

Environment:

• Eclipse 4.31
• TM4E 0.13.0, LSP4E 0.18.4

[sebthom]

I can reproduce this with the latest eclipse and tm4e release.

@mickaelistria any idea how to address this?