Patch Guidelines

As an open source project, JOSM is coded and maintained by volunteers in their spare time. You too are very welcome to contribute to the development. — So you have improved the JOSM code and you'd like the share the changes with the community? The following guidelines provide hints, how you can make the integration as smooth as possible.

• Use the command svn diff or the tools of your IDE, to create a patch file rather than sending us complete .java files.
• In order to submit the patch, open a new ticket and attach the file (use the .diff or .patch file extension). Put the term [PATCH] in the subject line of your ticket, so it is displayed in the list of pending patches.
• Remember to "svn add" new files.
• Do not zip your patch file.
• If you like to add more that 2-3 images, attach them in zip archive. Tell us, where the images should be copied to.
• Even if you changed just a single file, create the patch from the root folder of the JOSM source repository.
• Keep the patch as readable as possible: Do not correct the formatting / indentation of any code that need not be changed. Do not unnecessarily reorder methods, etc. (Improvements of the documentation are always welcome, though.)
• If you have multiple related changes, it is usually better to combine them all in one big patch, rather than attaching a long list of diffs. However, sometimes it may be useful to split the more controversial parts of the changes from those that can be applied without discussion.

Please be patient—there can be various reasons, why your patch is not dealt with. If you don't get any reaction for two weeks, it may be a good idea to bring the topic up again and ask for a status update.