Emacs support: numerous changes.
Most SCM commands now work in derived buffers (e.g. diff viewing
buffers) as well as buffers backed by files.
diff and log now work properly on repositories and files.
Commit support is more solid.
Doc strings are better.
#!/bin/sh
mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m "test" -d "0 0"
hg verify
hg parents
hg status
hg undo
hg verify
hg parents
hg status