Investing in bug reports pays off

Document compatibility between office suites is a common concern for LibreOffice users. People take sample documents, expecting a pixel-perfect similarity with other office applications and rightly so. While we cover most aspects of formats outside the OpenDocument Format specification, LibreOffice’s native format, there are pieces that have not been implemented yet (for example smooth shadows, which have been implemented recently and will be available in LibreOffice 7.1). Of course we sometimes fail as well, like any other software producer. Microsoft’s “transitional” formats often include undocumented or obscure content that is hard for other office suites to parse.

One enormous advantage of open source software is that you can talk more or less directly to the developers. All bug reports and enhancement requests are taken seriously and will receive immediate response unlike what happens when you complain about issues to companies without open development models. Unfortunately not everyone knows about this advantage so we thought it’s time to recall.

The people doing quality assurance for LibreOffice is an ever-changing group of around 30 contributors. They analyse user reports tirelessly and always appreciate problem descriptions delivered in a clear and understandable way. In a recent article about LibreOffice appearing on dedoimedo.com, several bugs were reported, but in a rather incomplete way. It is understandable, if a journalist does not want to create proper reports in our bug tracker on top of writing an article. Maybe there is a middle-ground, though.

Simply linking to the problematic Microsoft Office templates would have made the work of the quality assurance team much easier. Now the templates shown in the screenshots had to be discovered through detective work on the MSO template site. Particularly unfortunate was the case of a template, which refused to open properly. There is no way of figuring out the identity of the document and the author never replied to an email requesting for more information. On the other hand, it might be time for the QA team to again methodically go through every single template on the MSO site – such work has been done before, resulting in many solved incompatibilities.

Detailed comments on the document template issues described in the Dedoimedo article

Fashion newsletter template: Some obstacles need to be considered regarding cross-application and probably also cross-platform compatibility questions. Documents written on one system might use a font that is not available on another. The article mentioned above talks about the word FASHION breaking into two lines in the MSO Fashion newsletter template. The reason for this wrapping is that the author did not notice they were missing the Century Gothic font. This can be seen in the Formatting toolbar, where the font name appears in italics and hovering over it shows a tooltip saying that the font is not available and has been substituted.

The author refers to an image border missing on the first page. Probably they meant the whole page margin on the right. This issue was not seen on Windows or Linux by testers.

The image stretching issue had not been reported before. The newly-created report contains an analysis on a level that is typical to the QA team. However, the QA team will gladly conduct further analysis on reports with less details. The image stretching issue is the same that is seen in the restaurant newsletter template

An issue not mentioned in the article is the incorrect lengths of the fuchsia-coloured lines on the first page. This was analysed through binary bisecting and found to have been reported before. This issue is an unfortunate side effect of a complex internal improvement in the handling of shapes.

Restaurant newsletter template: Testers did not see the issue with the placement of the restaurant logo.

Based on data in our bug tracker, LibreOffice saw over 330 fixes or feature implementations for MSO and RTF document issues in 2019. The number for 2020 is already over 330 at this point. The real numbers are likely higher as not every code change is connected with a report. These statistics clearly indicate that document compatibility is seeing significant investments from the commercial ecosystem and volunteers alike.

LibreOffice quality assurance is aided by many automated systems. One of these is called “Office interoperability tools”. It compares the output of Microsoft Office and LibreOffice over a huge corpus of documents in order to find regressions. Manual testing and problem discovery is still needed – we can’t automate the testing of issues we don’t know about.

As mentioned, while Microsoft’s “transitional” formats continue to use undocumented or cryptic content, which makes life difficult for other office suites, there’s a limit to what we can do. Ultimately, it would be better if everyone used the OpenDocument Format, to ensure maximum interoperability.

If you want to learn how to create high quality bug reports, please read our dedicated guide in The Document Foundation wiki.