When it comes to newly created or modified files, IntelliJ IDEA introduces the concept of a changelist. A changelist is a set of file modifications that represents a logical change in the source. Any modified file will go to the Default changelist. You can create new changelists if you like. The changes contained in a specific changelist are not stored in the repository until committed. Only the active changelist contains the files that are going to be committed. If you modify the file that is contained in the non-active change list, there is a risk that it will not be committed. This takes us to the last section of the common VCS settings at Settings | Version Control | Changelist conflicts. In this section, you can configure the protection of files that are present in the changelist that is not currently active...