Test that rename detection works
  $ . "$TESTDIR/testutil"

  $ cat >> $HGRCPATH <<EOF
  > [diff]
  > git = True
  > [git]
  > similarity = 50
  > EOF

  $ git init -q gitrepo
  $ cd gitrepo
  $ for i in $(seq 1 10); do echo $i >> alpha; done
  $ git add alpha
  $ fn_git_commit -malpha

Rename a file
  $ git mv alpha beta
  $ echo 11 >> beta
  $ git add beta
  $ fn_git_commit -mbeta

Copy a file
  $ cp beta gamma
  $ echo 12 >> beta
  $ echo 13 >> gamma
  $ git add beta gamma
  $ fn_git_commit -mgamma

Add a submodule (gitlink) and move it to a different spot:
  $ cd ..
  $ git init -q gitsubmodule
  $ cd gitsubmodule
  $ touch subalpha
  $ git add subalpha
  $ fn_git_commit -msubalpha
  $ cd ../gitrepo

  $ rmpwd="import sys; print sys.stdin.read().replace('$(dirname $(pwd))/', '')"
  $ clonefilt='s/Cloning into/Initialized empty Git repository in/;s/in .*/in .../'

  $ git submodule add ../gitsubmodule 2>&1 | python -c "$rmpwd" | sed "$clonefilt" | egrep -v '^done\.$'
  Initialized empty Git repository in ...
  
  $ fn_git_commit -m 'add submodule'
  $ sed -e 's/path = gitsubmodule/path = gitsubmodule2/' .gitmodules > .gitmodules-new
  $ mv .gitmodules-new .gitmodules
  $ mv gitsubmodule gitsubmodule2
  $ git add .gitmodules gitsubmodule2
  $ git rm --cached gitsubmodule
  rm 'gitsubmodule'
  $ fn_git_commit -m 'move submodule'

  $ cd ..
  $ hg clone -q gitrepo hgrepo
  $ cd hgrepo
  $ hg log -p --graph --template "{rev} {node} {desc|firstline}\n{join(extras, ' ')}\n\n"
  @  4 8ef5468692d8a63a2a56d35540ccc2a83970daf1 move submodule
  |  branch=default
  |
  |  diff --git a/.gitmodules b/.gitmodules
  |  --- a/.gitmodules
  |  +++ b/.gitmodules
  |  @@ -1,3 +1,3 @@
  |   [submodule "gitsubmodule"]
  |  -	path = gitsubmodule
  |  +	path = gitsubmodule2
  |   	url = ../gitsubmodule
  |  diff --git a/.hgsub b/.hgsub
  |  --- a/.hgsub
  |  +++ b/.hgsub
  |  @@ -1,1 +1,1 @@
  |  -gitsubmodule = [git]../gitsubmodule
  |  +gitsubmodule2 = [git]../gitsubmodule
  |  diff --git a/.hgsubstate b/.hgsubstate
  |  --- a/.hgsubstate
  |  +++ b/.hgsubstate
  |  @@ -1,1 +1,1 @@
  |  -5944b31ff85b415573d1a43eb942e2dea30ab8be gitsubmodule
  |  +5944b31ff85b415573d1a43eb942e2dea30ab8be gitsubmodule2
  |
  o  3 82b69d514926123f7d83b6a8fb5b041bc79c5af9 add submodule
  |  branch=default
  |
  |  diff --git a/.gitmodules b/.gitmodules
  |  new file mode 100644
  |  --- /dev/null
  |  +++ b/.gitmodules
  |  @@ -0,0 +1,3 @@
  |  +[submodule "gitsubmodule"]
  |  +	path = gitsubmodule
  |  +	url = ../gitsubmodule
  |  diff --git a/.hgsub b/.hgsub
  |  new file mode 100644
  |  --- /dev/null
  |  +++ b/.hgsub
  |  @@ -0,0 +1,1 @@
  |  +gitsubmodule = [git]../gitsubmodule
  |  diff --git a/.hgsubstate b/.hgsubstate
  |  new file mode 100644
  |  --- /dev/null
  |  +++ b/.hgsubstate
  |  @@ -0,0 +1,1 @@
  |  +5944b31ff85b415573d1a43eb942e2dea30ab8be gitsubmodule
  |
  o  2 79563b42ed93cd47601aec11694f4e0df48457e7 gamma
  |  branch=default
  |
  |  diff --git a/beta b/beta
  |  --- a/beta
  |  +++ b/beta
  |  @@ -9,3 +9,4 @@
  |   9
  |   10
  |   11
  |  +12
  |  diff --git a/beta b/gamma
  |  copy from beta
  |  copy to gamma
  |  --- a/beta
  |  +++ b/gamma
  |  @@ -9,3 +9,4 @@
  |   9
  |   10
  |   11
  |  +13
  |
  o  1 d1c40364c3c996350da6963e605df8269db8e311 beta
  |  branch=default
  |
  |  diff --git a/alpha b/beta
  |  rename from alpha
  |  rename to beta
  |  --- a/alpha
  |  +++ b/beta
  |  @@ -8,3 +8,4 @@
  |   8
  |   9
  |   10
  |  +11
  |
  o  0 0c233c2e91d64435bf329075bc0e7e858bc3b07c alpha
     branch=default
  
     diff --git a/alpha b/alpha
     new file mode 100644
     --- /dev/null
     +++ b/alpha
     @@ -0,0 +1,10 @@
     +1
     +2
     +3
     +4
     +5
     +6
     +7
     +8
     +9
     +10