For developing: released.
For testing if your bug is indeed fixed (and will be in the next release): Snapshot
As explained by others: Lazarus 1.0 can not be changed. No release will ever be changed after it was published.
If bugs have been fixed, then there will eventually be a new release.
If someone knew in which revision the above bug was fixed (if it indeed is fixed) then you could patch your copy of Lazarus. But so far it is not known.
It is not even known if it is fixed or not. And only you can tell: From comments (I do not use LazReport), I read that no one is able to reproduce the issue. But they all tested on snapshots.
That may mean:
- The issue is fixed and the fix will be in a future release (hopefully, but not necessarily the next).
- Or the issue is not fixed, but we do not know how to reproduce. It may even be, that it depends on some setting (e.g. gtk theme or window-mgr or ...) that you have. It would still be a bug. But it will take a lot of effort to find out what it is.
Only if it is known which one is the case, only then the next step can be decided.