This page describes a proposal that was rejected for core Mercurial. However, it may be implemented as a third party extension.
Mutable Branches
A recurring compliant against named branches is that the name is permanent. This page describes a backward-compatible proposal to separate a branch's identity from its name.
Contents
1. Visioning Branch Names
An .hgbranches file in the working directory will keep a mapping of branch IDs to their names. When a new branch is created, the changeset's branch field will be set to a unique ID. An entry will then be made in .hgbranches, mapping the branch's ID to its name.
There are no changes to Mercurial's UI, other than not scolding the user when they create a new branch.
2. Conflicts
If conflicting changes have been made to .hgbranches on different branches, or if it contains conflicting entries, this will be resolved by the same rules that apply to .hgtags.
3. Local Branches
If the user creates a local branch which they do not intend pushing, it can be recorded in .hg/localbranches.
4. Backwards Compatibility
If a branch ID is not recorded in .hgbranches or .hg/localbranches, the ID will be used as the branch name. Thus, existing branches can be used (and renamed) without any modifications. If the branch is renamed, older clients will continue to use the old name.
5. Forwards Compatibility
Future development could add other fields to .hgbranches, such as description or owner.
6. Similar Implementations
The hg-ibranch extension implements a similar concept, but uses tip markers instead of .hgbranches.