Memory Leak with Textfields and non-embedded chars

I came across a memory leak with textfields using non-embeddedd chars.

The issue occurs on Windows desktop with AIR 20 SDK and Flex 4.14.1.

The textfield I'm using is the spark Label (however, from a post on Stackoverflow (http://stackoverflow.com/questions/23271354/as3-textfield-and-textformat-memory-leak-other-bitmap-memory/), I would assume that this does also occur for Flash TextFields/Textfields based on FTE).

In Adobe Scout I do see a memory increase for "Bitmap" -> "Other Bitmap Memory" when I'm adding Labels with non-embedded chars.

When I remove the textfields, the memory will remain the same and not decrease as one would expect.

There is no situation where the memory will ever decrease - Garbage Collector System.gc() does also not work.

The renderMode in the app descriptor XML does affect this behaviour as the following:

- renderMode cpu:

Memory does never increase

- renderMode gpu:

Memory does always increase

- renderMode direct:

Memory does only increase when application is fullscreen (StageDisplayState.FULL_SCREEN)

-renderMode auto:

same as direct