convert: readd --filemap To handle merges correctly, this revision adds a filemap_source class that wraps a converter_source and does the work necessary to calculate the subgraph we're interested in. The wrapped converter_source must provide a new getchangedfiles method that, given a revision rev, and an index N, returns the list of files that are different in rev and its Nth parent. The implementation depends on the ability to skip some revisions and to change the parents field of the commit objects that we returned earlier. To make the conversion restartable, we assume the revisons in the revmapfile are topologically sorted.

convert: move filemapper class to a separate file

convert: disable current --filemap support The --filemap support in hg convert doesn't handle merges correctly. (And after 33015dac5df5 I managed to break it even for simple cases where we don't want the first revision.)

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.

convert: pass the order of the revmapfile to the converter_source The entries in this file are supposed to be topologically sorted and this may be useful for a converter_source.

Merge with crew

merge: add debug diagnostics for findcopies