When a fieldset is not using any HTML classes, it defaults the class to the name of the fieldset.
For example, if a fieldset (assuming div) is called "Row One", the class will look like
<div class="row-one views-fieldset" data-module="views_fieldsets">
However, if a custom class is used on the fieldset, the fieldsets "name" class is removed.
Example using the custom class "row-color"
<div class="row-color views-fieldset" data-module="views_fieldsets">
1) Install Views Fieldset and setup accordingly
2) Test between a blank "HTML class" and a custom "HTML class" within a fieldset field.
There should be consistency. If the class is present when no custom class is used, then it should be present if a custom class is used. Otherwise, there should be NO default class and it is explicitly expected a custom class will be used.
I just ran into this issue by styling for the default name class. As soon as I added some custom classes, I had to re-populate the default class in with the custom classes.
Test, confirm, fix
If fixed, this may end up causing duplicate classes for some situations. It shouldn't be a problem, however it might be something worth mentioning in patch notes if this is ever fixed and committed.
Closed: outdated
2.3
Code
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.
Helping co-maintain this module for D10 going forward. Don't plan on doing any work with D7 unless something comes up for review.
Since D7 version of this module hasn't had a release in 5+ think it's safe to close out so that focus can stay on D10+