When a wiki is renamed (=its database name and/or table prefix is changed) the existing Flow discussions are lost because the wiki ID (given by MediaWiki’s function wfWikiID() is changed.
I propose to create a maintenance script to change the database columns where this reference is written. Probably this script will have two mandatory arguments: the old name and the new name; possibly one can be automatically retrieved if the script is run before or after the rename operation.
I did the following operations in database in a wiki and it globally works (*):
UPDATE flow_ext_ref SET ref_src_wiki = 'newWikiID' WHERE ref_src_wiki = 'oldWikiID'; UPDATE flow_revision SET rev_user_wiki = 'newWikiID' WHERE rev_user_wiki = 'oldWikiID'; UPDATE flow_revision SET rev_mod_user_wiki = 'newWikiID' WHERE rev_mod_user_wiki = 'oldWikiID'; UPDATE flow_revision SET rev_edit_user_wiki = 'newWikiID' WHERE rev_edit_user_wiki = 'oldWikiID'; UPDATE flow_tree_revision SET tree_orig_user_wiki = 'newWikiID' WHERE tree_orig_user_wiki = 'oldWikiID'; UPDATE flow_wiki_ref SET ref_src_wiki = 'newWikiID' WHERE ref_src_wiki = 'oldWikiID'; UPDATE flow_workflow SET workflow_wiki = 'newWikiID' WHERE workflow_wiki = 'oldWikiID'; UPDATE flow_subscription SET subscription_user_wiki = 'newWikiID' WHERE subscription_user_wiki = 'oldWikiID';
(The last table was empty, so I’m less sure, but it seems it should be changed too.)
(*) I have a minor issue because old topics have no entry in the MediaWiki table 'page' (and hence are red links), but possibly it is linked to activation process (I guess I ran the populateContentModel – transition to content models – before I executed the UPDATEs above and hence the script considered it was non-local pages). If a 'FlowRenameWiki.php' script is created it should be documented if it should run before or after the populateContentModel script in the case of a transition.