NAVIGATION Are we aware of a behaviour change that makes all

Question

NAVIGATION Are we aware of a behaviour change that makes all navigation actions re add routes already present For example I have root nav graph passed to NavHost and A B destinations If A is start destination then back stack looks like ` root A ` When I navigate from A to B then I would expect to have ` root A B ` like it was before but now in latest navigation versions I still haven t figured out what version exactly changed this I m getting ` root A root B ` This can have impact if the user is calling `popUpTo root ` Is this known and intended or a regression

Rafael Costa · Answer

< Ian Lake> again I hope you don t mind my audacity of tagging you but I feel like you are interested in the topic and can probably give me an answer in 1min within reading the question smile

Ian Lake · Answer

Unless you specifically navigate to `root` which will create a new copy of `root` on the back stack navigating to `B` should reuse the existing copy File a bug if you are seeing something different

Rafael Costa · Answer

Perfect this is all I needed to know thanks Ian I will just make sure it s nothing on my side before I submit something But it does look like if nothing changes and I just change navigation dependency version it starts working as expected so even if I m doing something weird it would still be some kind of breaking change But I want to confirm all this first now that I know this is not the intended behaviour slightly smiling face

Rafael Costa · Answer

Just in case you re curious I found this change in NavController class that seems suspicious method `addEntryToBackStack` Still gonna do more tests though

Rafael Costa · Answer

So yes I was able to confirm that this change which was introduced in `2 6 0 alpha05` is the cause of the behaviour I m seeing Only by changing from `2 6 0 alpha04` to `2 6 0 alpha05` I start seeing this behaviour and it matches the left and right side of the diff image shown above

Rafael Costa · Answer

I ll report it as soon as I can

Rafael Costa · Answer

reported here <https issuetracker google com issues 275407804>

Rafael Costa · Answer

I learnt while preparing this issue that the same doesn t happen for nav graphs other than the root one that we pass to NavHost call If we add a nav graph as the only direct child of this root we won t see this issue Still it feels like quite problematic and can introduce bugs for anyone relying on this root and popping to it since now it would only pop their top most destination

Rafael Costa · Answer

Issue fixed on 2 6 0 alpha09 raised hands

Ian Lake · Answer

Thank you for filing the issue it was very helpful