EDIT

to check if it works you have to delete eu.etaxonomy.taxeditor.store.prefs in folder .cdmLibrary/.metadata/.plugins/org.eclipse.core.runtime/.settings
to get rid of stored preferences

This ticket is difficult to review before the release so we will do the review afterwards.

If no entry exists in eu.etaxonomy.taxeditor.store.prefs everything works as expected as far as I can see. Meaning, that stable versions use ..\stable as update site, nightly versions use ..\nightly.

Remaining problem is that if this value is changed for some reason it is still stored in a user wide location instead of being instance dependent. If one has >1 instances and both stable and nightly versions this may create problems.

However, the problem is small as usually one may not need to change the value of the preference at all so except for users who have already installed old versions on there machine it is not expected that anybody is explicitly setting this value anymore.

We may create a new ticket for this remaining issue with low priority - or just leave it as it is and mentioning here that the second part of the ticket was not implemented - on purpose at it is not relevant enough.

I vote for not adding a new issue. I think the standard user only runs one instance which usually is the stable release. So once the update site is correctly configured (either the user already has some pref files which he/she deletes or it is correctly set up by first installation) the updates should always work for new releases.

I agree that we can close the ticket as the remaining issue is small and since than most users will have reinstalled there instances.