Some bugs get reported more than once. That’s why we’ve got the dupe finder.
Some duplicate bugs slip through the dupe finder. Really common issues get quite a few dupes and someone from the relevant project usually goes through and marks them as duplicates of the master bug where the actual discussion and tracking is taking place.
There has been a really annoying bug in the way Launchpad has handled all this, though, and Deryck‘s just fixed it
Let’s say you’ve got a bug report that has a few duplicates attached to it. You then discover that, actually, there’s an older bug with a more mature discussion and that, really, that’s the master bug. Until now, before you marked your bug as a duplicate of the master, you’d first have to take all the dupes of your bug and manually make them dupes of the master.
Still with me?
For a busy bug with many dupes, some of which have their own dupes, that’s a real disincentive to clearing up the multiple duplicates and gathering everything together on the one true master bug.
Now, though, simply mark your bug as a duplicate and Launchpad will automatically transfer your bug’s dupes to the new master bug.