 Minun nimi on Ilmarilla Uhokangas, ja minulla on valmis videossa, joka on tuntuu kaupungin. Kaikki on fremaa, jotta on kokemukkaapuolta, jossa on lippuja. Opaa kokemukkaapuolta on toinen kokemuksesta, jota on kokemukkaapuolta. Kokemukkaapuolta ja yksi kokemukkaapuolta on yksi kokemuksessa, mutta mitä on tärkeää, että se on seuraavaa kokemuksessa? Let's find out by examining the work of a bug reporter going by the nickname Telesto. First off, I want to say that even though we are all tired of looking at bugzillas crusty old interface while waiting for the update that never comes, this presentation would not have been possible without its advanced search capabilities. It really is the ultimate tool for easy research into bug reports. Since 2016 Telesto has created over 3000 reports in our bugzilla. The vast majority of them are bugs while they do include about 200 feature requests. The volume of Telesto's bug reports is anomalous. As such it has even annoyed some people. I admit I have sometimes felt overwhelmed by the amount of confirming work required. However, being bothered by the reports is really more of an attitude problem. Consider the following facts. He is friendly, he is cooperative, he uses advanced bug analysis techniques time permitting. So what if he has opinions on how LibreOffice should work? It's not a crime. Dealing with such an active reporter is possible because we have always had a strong quality assurance team. Telesto has naturally grown into the role of a quality assurance contributor, having so far been active in over 2000 reports created by others. As I know he gives so much support to others, I have no problem testing 100 reports in a row concerning some specific functionality has taken interest in. Out of his own reports over 1300 are still open. Over 500 were closed with a known fix, while over 260 are works for me, usually meaning that the problem is gone without us knowing the exact code change. When Telesto started he was focusing on Mac OS, later also using Windows. Recently he even began testing on Linux. A major inspiration for Telesto to start contributing more was a private email from a long time Mac OS tester, Steve. In the email Steve invited Telesto to join the QA team. Small gestures can sometimes have a big impact. A clear majority of his reports concern writer, which is admittedly our most actively developed application. Great artists famously have periods of particular styles and influences, like Picasso's periods called blue, rose, analytic cubism and synthetic cubism among others. It is only logical that a great bug reporter would have similar phases. Let's have a look at Telesto's major teams while also observing some actual bug-triaging action. I recorded the testing videos while reproducing unconfirmed reports just for this presentation. Telesto really started with performance issues. This is a team that he has continued to explore at times quite intensively. Sometimes processor use goes through the roof, while sometimes memory use related to some functionality has increased suspiciously. On Windows he has used process monitor to even detect unnecessary file access activity. The discussions around these resource use reports have made the quality assurance team more aware of the decisions developers make in balancing the uses of CPU memory and disk storage. I'm going to do a specific set of steps that leads to a table layout loop. I select all and copy. I open a new document. I paste twice. I undo twice. I start a performance trace for the LibreOffice process. I paste once. I wait for a while as the perf trace gathers data. I hit Ctrl C to cancel out of perf. I run a command that creates a flame graph of the perf data. The flame graph can be observed in Inkscape for example. The plateaus in the landscape tell us of curiously long times spent in a specific function. We see lots of time is spent in managing undo and thread locking. This is about changing anchoring type being abnormally slow. I start a perf trace. I change the anchoring of the image to character. I create the flame graph from the perf data. Here we see a long time spent thinking about line breaks with the help of the international components for Unicode ICU library. Early on Telesto was creating many reports for Microsoft Word document issues. This team has also been present throughout his work. So far he has several hundred reports related to Microsoft Office compatibility under his belt. In 2017 Telesto noticed he can make weird stuff happen using the undo and redo functionality in various command sequences. Undo is indeed quite a tricky problem area in software development. And with his hundreds of reports Telesto has certainly proven that we need to work on the robustness of our implementation. This is about undo messing up numbering size in a list. I select all. I toggle the numbering two times. I hit undo twice. This is about unexpected undo behavior while editing text in a text box. I edit the text box. I select all and cut. I hit undo. After I focus outside the text box and hit undo again the bullets reappear. Copying and pasting is something that sounds so simple and innocent that an average guy on the street would never guess it to be an implementation minefield. There was a big spike in past issues reported by Telesto in 2018 and the topic is still near to his heart. Often it is part of some dance choreography including undo and redo steps. In this issue pasting drops images. I save the file as docx and reload. I select everything and copy. I paste as rtf. Most images are now gone. Rider layout is another complex puzzle and anchoring of objects in the document canvas is one special field in this rocket science. In 2020 Telesto decided to go after anchoring issues with the vengeance. There were of course some unavoidable philosophical discussions on the very nature of anchoring. Here we have an image anchored to paragraph refusing to move to the left. I select the image and hold down shift key to constrain the axis of the movement. I drag to the left and the image doesn't move. Dragging it diagonally gives a different result. This is a bug that took me into a rabbit hole. It is about the anchoring type of a frame changing from two character to paragraph when saving as docx. Telesto reported the bug is not seen in LibreOffice 4.2 but is already in 4.3. I decided to do a binary bisect of it. I use a virtual machine with an Ubuntu from 2014 because that is the easiest way to run these older LibreOffice versions. The 4.3 repository has all kinds of issues. Here I do a checkout of the last commit in the repo and run LibreOffice with the fallback UI gen as that is the only UI where saving works reliably with this repo. I save the file as docx. I reload the file. The anchor is indeed to paragraph. In the oldest commit in the repo it stays as two character. Now there is an interesting plot twist. After an annoying bisecting session with lots of crashes forcing me to skip over commits, I discovered that I should have activated experimental mode before starting to test. I did another bisecting run with experimental mode turned on and found a more useful commit which was about switching from VML to drawing ML when exporting text frames into docx. It has to be mentioned that Telesto has reported at least 300 bugs that make LibreOffice crash. Then there are those over 2,000 reports by other users where he has helped in some way. He has done countless of bisecting analysis which means to discover the exact code chains that caused a bug. He has tirelessly organized reports to reduce the amount of duplication and redundancy pointing people to helpful information. At times developers have given special tanks to Telesto. There was an annoying old clipboard bug where the paste entry in the context menu in writer would be disabled while the keyboard shortcut worked. Mike Kaganski fixed the bug while commenting. I must express greatest gratitude to Telesto for a nice reliable test case in a clear bug report. In his message for a commit fixing a macOS issue where printing something in portrait mode resulted in it being in landscape orientation, Tour Lilquist wrote, thanks to Telesto for noticing this copy paste issue. In this case Telesto had located a relevant clue in the source code. In addition to bug analysis Telesto has even contributed straight up bug fixes. These fixes all happened in 2018. He fixed a macOS issue where all buttons were marked with blue color as if they were default. Developer Tour Lilquist commented, thanks this misfeature has been annoying me for a while whenever I run LibreOffice on my Mac. He fixed a macOS issue where some windows incorrectly opened as tabs. He fixed a regression where the cursor was not focused on the document canvas with new writer or calc files. Thank you for your attention and thanks to Telesto for all the work. I hope the rest of your reports get fixed or implemented and the mysteries get documented.