tests/test-clone-pull-corruption

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
#
# Corrupt an hg repo with a pull started during an aborted commit
#

# Create two repos, so that one of them can pull from the other one.
hg init source
cd source
touch foo
hg add foo
hg ci -m 'add foo'
hg clone . ../corrupted
echo >> foo
hg ci -m 'change foo'

# Add a hook to wait 5 seconds and then abort the commit
cd ../corrupted
echo '[hooks]' >> .hg/hgrc
echo 'pretxncommit = sleep 5; exit 1' >> .hg/hgrc

# start a commit...
touch bar
hg add bar
hg ci -m 'add bar' &

# ... and start a pull while the commit is still running
sleep 1
hg pull ../source 2>/dev/null

# see what happened
wait
hg verify