Changing column lookup value deletes associated column icon rules

[ownedbycats]

Calibre 5.5

Only tested with column icons. Doubt this would apply to emblems, perhaps to column-specific colouring rules if it didn't just fall back to "all columns."

Steps to replicate:

Create a #test column.

Create two rules in column icons:
a) Have one of them add the icon to #test if Title is set.
b) Have the second add an icon to Title if #test is set.

Change the lookup name of #test to #test2.

Rule b) automatically converts to an advanced rule based on the now-missing #test, but a) disappears entirely without any chance to modify it to the correct lookup name beforehand.

I assume that Calibre treats changing the lookup name the same as deleting it, but it's not very obvious that the user should switch any rules over to a temporary column first.

If there's no way to detect the change, other solutions:
a) Check for any associated rules upon rename/delete, warn the user, and ask for confirmation;
b) have any unassociated rules fall back onto one of the default untouchable columns;
c) Allow icon rules to not be associated with a column and just blank it out.

Thank you.

[Kovid Goyal (kovid)]

This is not worth the effort for me personally. If some one else wants to implement it, I will be happy to supply any needed guidance. If so, re-open the ticket and we can discuss it.

 status wontfix