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.
#!/bin/sh
mkdir r1
cd r1
hg init
mkdir a
echo foo > a/f
hg add a
hg ci -m "a/f == foo"
cd ..
hg clone r1 r2
cd r2
hg mv a b
echo foo1 > b/f
hg ci -m" a -> b, b/f == foo1"
cd ..
cd r1
mkdir a/aa
echo bar > a/aa/g
hg add a/aa
hg ci -m "a/aa/g"
hg pull ../r2
hg merge
hg st -C