convert: allow the converter_source to say "skip this revision" If getchanges returns a string, it's assumed to be the id of an already converted revision. We map the current revision to the same revision this converted revision was mapped to. To allow skipping a root revision, getchanges can return the special string 'hg-convert-skipped-revision' (a.k.a. common.SKIPREV), which hopefully won't clash with any real id. The converter_source is responsible for rewriting the parents of the commit objects to make sure the revision graph makes sense.

adding a/f
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
copying a/f to b/f
removing a/f
adding a/aa/g
pulling from ../r2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
M b/f
A b/aa/g
  a/aa/g
R a/aa/g
R a/f