Component used: Navigation

Version used: 2.6.0-alpha05

Devices/Android versions reproduced on:

Not relevant, it will happen on all.

If this is a bug in the library, we would appreciate it if you could attach: Sample project to trigger the issue.

I'll add a couple of simple kotlin files instead, just use them with any version after 2.6.0-alpha05 navigation dependency and you'll be able to reproduce it.

MainActivity_rook.kt File

If we add destinations directly on "root" (route passed to NavHost call), then this will be the log of the back stack as we navigate:

stack = []
stack = [root, home]
stack = [root, home, root, screen_two/{id}]
stack = [root, home, root, screen_two/{id}, root, screen_three]

MainActivity_no_root.kt File

If we add a navigation graph ("home_graph") as the only direct child of "root" and add destinations on that instead, it will work as expected, we'll see this:

stack = []
stack = [root, home_graph, home]
stack = [root, home_graph, home, screen_two/{id}]
stack = [root, home_graph, home, screen_two/{id}, screen_three]

This was a breaking change that could introduce bugs for anyone relying on that "root" sent on the NavHost and popping up to that, since after updating navigation it would instead just pop their last screen.