Comment 24 for bug 1093765

Why do you expect attributes to be consistent when switching from one style to another? If your default paragraph uses a (directly applied) italic font style it will be removed when switching to any other style.

We could turn this question around and ask what you expect when switching from one style to another. Meaning whether all or just the different attributes should be overwritten. Let's say the text is Text Body with the special attribute italic (whether set directly or via style modification doesn't matter). Switching to Heading 1 could mean you expect the font size larger and the bold weight to be applied - in addition to the italic weight. This does not solve the use case to explicitly switch off an attribute, eg. H1 in bold but H2 not.

The issue is clearly NAB.