Contributing To Fossil

Users are encouraged to contributed enhancements back to the Fossil project. This note outlines some of the procedures for making useful contributions.

1.0 Contributor Agreement

In order to accept your contributions, we must have a Contributor Agreement (PDF) (or as HTML) on file for you. We require this in order to maintain clear title to the Fossil code and prevent the introduction of code with incompatible licenses or other entanglements that might cause legal problems for Fossil users. Many larger companies and other lawyer-rich organizations require this as a precondition to using Fossil.

If you do not wish to submit a Contributor Agreement, we would still welcome your suggestions and example code, but we will not use your code directly - we will be forced to re-implement your changes from scratch which might take longer.

2.0 Submitting Patches

Suggested changes or bug fixes can be submitted by creating a patch against the current source tree. Email patches to Be sure to describe in detail what the patch does and which version of Fossil it is written against.

A contributor agreement is not strictly necessary to submit a patch. However, without a contributor agreement on file, your patch will be used for reference only - it will not be applied to the code. This may delay acceptance of your patch.

Your patches or changes might not be accepted even if you do have a contributor agreement on file. Please do not take this personally or as an affront to your coding ability. Sometimes patches are rejected because they seem to be taking the project in a direction that the architect does not want to go. Or, there might be an alternative implementation of the same feature being prepared separately.

3.0 Check-in Privileges

Check-in privileges are granted on a case-by-case basis. Your chances of getting check-in privileges are much improved if you have a history of submitting quality patches and/or making thoughtful posts on the mailing list. A contributor agreement is, of course, a prerequisite for check-in privileges.

Contributors are asked to make all non-trivial changes on a branch. The Fossil Architect (Richard Hipp) will merge changes onto the trunk.

Contributors are required to following the pre-checkin checklist prior to every check-in to the Fossil self-hosting repository. This checklist is short and succinct and should only require a few seconds to follow. Contributors should print out a copy of the pre-checkin checklist and keep it on a notecard beside their workstations, for quick reference.

Contributors should review the Coding Style Guidelines and mimic the coding style used through the rest of the Fossil source code. Your code should blend in. A third-party reader should be unable to distinguish your code from any other code in the source corpus.

4.0 Testing

Fossil has the beginnings of a release checklist but this is an area that needs further work. (Your contributions here are welcomed!) Contributors with check-in privileges are expected to run the release checklist on any major changes they contribute, and if appropriate expand the checklist and/or the automated test scripts to cover their additions.

5.0 See Also