>Just add those files to the global gitignore on your machine While global gitignore is a nice feature, it won't protect users who do not know they need to create a global ignore file. Adding explicit excludes for well-known temporary files into PostgreSQL sources makes it easier to work with the sources for everybody. Less manual configuration is better for having a productive environment.
On top of that, there is even a use-case for having .idea folder in Git: .idea/icon.png and .idea/icon_dark.png files are displayed in JetBrains IDEs so the list of projects becomes easier to distinguish. AFAIK, a standard icon configuration does not yet exist: https://github.com/editorconfig/editorconfig/issues/425 Here's are samples: https://github.com/junit-team/junit5/blob/4ddc786728bc3fbc68d6a35d2eeeb63eb3e85609/.idea/icon.png , https://github.com/gradle/gradle/tree/1be71a9cd8882b08a9f8728d44eac8f65a33fbda/.idea Vladimir