Last week I had fixed a trivial bug (a leftover from a former change where a function’s return was changed, but one place of its usage managed to escape to be not converted to properly treat the changed return). It seems to simultaneously have fixed a number of other bugs (the discussion may be found in the bug tracker issue). The little (a few characters) bug turned out to create both performance issues, and clipping of characters, so it had big impact on LibreOffice on Windows (with DirectWrite, e.g. when OpenGL is used).
The problem became trivial both to find and fix, because of great bug report by Telesto, who not only filed the report, but also had provided every relevant piece of information, including terminal output accompanied the problem manifestation. I cannot emphasize enough the importance of this: the effort of the bug reporter makes a difference. Without the effort, some problems remain very difficult for developers to be tracked down and get fixed.
I write this to praise Telesto‘s great job, and urge every reporter of a bug to follow this great lead.