This is a proposal for more obvious presentation of marking, and unmarking, duplicate bug reports.

If a bug report has duplicates of its own, it should have a "This report has ''n'' duplicates" section that expands to list those duplicates.

{{attachment:has-duplicates.jpg}}

Otherwise, if it is not already a duplicate, it should have a "Mark as a duplicate" section that expands to show the form for marking it as a duplicate. The field for entering the bug number should automatically be focused.

{{attachment:duplicate-before.jpg}}

Otherwise, it ''is'' already a duplicate, so it should have a "This is a duplicate of {number}: {summary}" section that expands to show a form for changing the duplicate marking. The field for entering a new bug number should automatically be focused.

{{attachment:duplicate-after.jpg}}

In either case, if the form is submitted with an error, the expandable section should still be expanded when the page reloads.

Without Java``Script, "This report has ''n'' duplicates", "Mark as a duplicate", and "This is a duplicate" should not be links. Instead, the duplicate section should be displayed inline, and "This report has ''n'' duplicates" and "Mark as a duplicate" (but not "This is a duplicate") should each be followed by a colon.