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
hg init a
cd a
cp $TESTDIR/binfile.bin .
hg add binfile.bin
hg ci -m 'add binfile.bin' -d '0 0'
echo >> binfile.bin
hg ci -m 'change binfile.bin' -d '0 0'
hg revert -r 0 binfile.bin
hg ci -m 'revert binfile.bin' -d '0 0'
echo % diff -r 0 -r 1
hg diff --nodates -r 0 -r 1
echo % diff -r 0 -r 2
hg diff --nodates -r 0 -r 2
echo % diff --git -r 0 -r 1
hg diff --git -r 0 -r 1
echo % diff --git -r 0 -r 2
hg diff --git -r 0 -r 2