rewind: make sure merge commits include files from p1 and p2 Otherwise rewinding a merge commit makes it lose all changes. This fix populates `updates` argument of rewriteutil.rewrite() with parent changesets. That argument is normally used for folding multiple changesets, but in this case it's simply used to include files from p1 and p2. Usually, rewrite() works fine using ctx.files(), but that function can return an empty list when ctx is a merge commit.

import hghave

@hghave.check("docgraph-ext", "Extension to generate graph from repository")
def docgraph():
    try:
        import hgext.docgraph
        hgext.docgraph.cmdtable # trigger import
    except ImportError:
        try:
            import hgext3rd.docgraph
            hgext3rd.docgraph.cmdtable # trigger import
        except ImportError:
            return False
    return True