Some folders are not removed from K9 after a refresh folder list action

Support
1

hi

this is a problem that has existed (for me) since Sep 2021.

EDIT: excitedly i believe i’ve isolated the problem!

Certain gmail folders that i renamed have resulted in both the old folder and the renamed one appearing in K9’s folder list

example:

“youtube audio” folder no longer exists in gmail (it’s been renamed) but still appears in K9

“youtube audio / headphone stuff” is the new name for “youtube audio” and also appears in K9

I was using K9 v5.806 on official build of android 9 on samsung s8 at the time.

I posted this as a bug here (some folders are not removed from K9 after a refresh folder list action · Issue #5661 · thundernest/k-9 · GitHub) - devs reported that it was a bug and had been fixed in beta.

I’ve just got an S22 handset, installed K9 v6.202 on latest OTA firmware (One UI 5.0 - android 13) and the problems have re-occurred

Symptoms
gmail IMAP folders that i have historically renamed - e.g. “youtube audio” :arrow_right: “youtube audio / headphone stuff” - get duplicated in K9

i.e. both the old folder and the renamed one both exist in K9’s folder list

Screenshot_20221104_142057_K-9 Mail
Screenshot_20221104_142057_K-9 Mail1080×2259 119 KB

testing
refreshed K9 folder list - no change

force stop k9 then run (and view folder list) - no change

force stop k9 then run then refresh folder list - no change

created new gmail folder (“test folder”) and refreshed folder list - new folder is visible

renamed gmail folder (“test folder”) to “test folder renamed” and refreshed folder list - revised folder name appears and old folder name is NOT visible (in K9)

renamed gmail folder (“test folder renamed”) to “test folder renamed again / but with a forward slash” and refreshed folder list - revised folder name appears AND old folder name is also visible (K9)

renamed gmail folder (“test folder renamed again / but with a forward slash”) to “test folder renamed yet again but with no forward slash” - revised folder name appears and old folder name has disappeared from K9 (yes!)

Conclusion
K9 can’t house-keep gmail folder names with a “/” in them correctly and leaves the old folder visible in K9

This conclusion appears consistent with all folder duplications that i can see in K9

Questions
Could the devs confirm this is a limitation of the use of this character (forward slash - apparently 002F in UTF-16)?

Does this limitation apply to other characters too?

Is this something they can adjust for in K9 code?

many thanks,

Gary

2

Any special character reserved in the Unix naming convention should not be used.

The forward slash (/) indicates a subfolder. Thus, K-9 properly displays the subfolder and its parent.

The same applies to the backslash () depending on the server OS and software.

1 Like
3

ok that makes sense. i’m familiar with filepath separators.

However, obviously gmail permits them and treats them as strings.

I had no reason to suppose K9 wouldn’t.

Any other special characters I need to avoid?

thanks,

Gary

4

IMAP supports arbitrary folder hierarchy separators. Slash is what Gmail returns as its hierarchy separator.