Retrieve Beyond Compare's path from registry
Switch from a hardcoded path to registry key to find Beyond Compare's
executable. Calling BCompare.exe works fine with version 3.0.14.
#!/bin/sh
# test dirstate._dirs refcounting
hg init t
cd t
mkdir -p a/b/c/d
touch a/b/c/d/x
touch a/b/c/d/y
touch a/b/c/d/z
hg ci -Am m
hg mv a z