Add "_conflicts" property to doc in map function when doc is in conflict

[snej]

It's poorly documented, but CouchDB adds a _conflicts property to the doc object passed to a map function, when the document is in conflict. From the CouchDB wiki:

Views only get the winning revision of a document. However they do also get a _conflicts member if there are any conflicting revisions. This means you can write a view whose job is specifically to locate documents with conflicts. Here is a simple map function which achieves this:

function(doc) {
  if (doc._conflicts) {
    emit(null, [doc._rev].concat(doc._conflicts));
  }
}

For compatibility it would be good to support this. I don't think it will affect performance: the SQLite engine already has to iterate over all the conflicting revisions, and the ForestDB engine has all the revisions readily available in the VersionedDoc object.

Note: We already support finding conflicts using _all_docs queries. In the REST API, add the query param ?include_conflicts=true or ?only_conflicts=true. In the native API use kCBLShowConflicts or kCBLOnlyConflicts. This is actually more convenient than having to create a special view just to find conflicts.

[borrrden]

I see you made some commits to the ForestDB storage engine in regards to this ticket, but not SQLite. Was SQLite already working? Or will it not be supported?

[pasin]

Yes, I just fixed the reference to the commit and PR. Please look at the PR link above.