Poisoned Changesets

Status: abandoned

Proponent: MartinGeisler

This proposal is inactive for 3 years, it's implementation have not been tested with the last version of Mercurial and are likely broken with them. See ChangesetEvolution for an alternative.

Original proposal: RFC: dealing with dead, anonymous feature branches

Implementation of proposal: http://bitbucket.org/mg/dead-branches

1. Definitions

We will use the following definitions:

poisoned changeset

a changeset with poisoned=1 in its extra dict.

dead head

a poisoned changeset that is also a head.

dead changeset

a changeset from which you can only reach dead heads.

dead branch

a set of dead changesets

2. Rules for Push

When pushing changesets, the following two rules are observed:

1. First, send changesets that are not on a dead branch.
2. Then, send changesets descending from what is now remote heads.

The discovery protocols gives us the heads of the common set of nodes. From these we can compute the changesets that are not on a dead branch (rule 1). We can then look at the remaining heads among the nodes in the common set and push descendants of these.

No new information is neede by this protocol, everything can be computed locally from information about the common set of nodes.

3. Rules for Pull

Symmetric to push, but the server needs to filter the changesets.

4. Use Cases

An experiment can be stopped, whether it has been pushed to another server or not:

A new commit is made:

A pull is made, bringing ind C, D, and E and it is decided that X is no longer is relevant:

CategoryDeveloper CategoryNewFeatures