tests/test-merge-default

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.

#!/bin/sh

hg init
echo a > a
hg commit -A -ma

echo a >> a
hg commit -mb

echo a >> a
hg commit -mc

hg up 1
echo a >> a
hg commit -md

hg up 1
echo a >> a
hg commit -me

hg up 1
echo % should fail because not at a head
hg merge

hg up
echo % should fail because \> 2 heads
hg merge

echo % should succeed
hg merge 2
hg commit -mm1

echo % should succeed - 2 heads
hg merge
hg commit -mm2

echo % should fail because at tip
hg merge

hg up 0
echo % should fail because 1 head
hg merge

true