displaying subtree merges

Hi, what is the best way to display merge commits of two branches with separate roots?

systemd and udev projects have merged [1], by a subtree merge of udev repo into systemd repo [2].

Displaying the commit shows:
% git show 19c5f19 --stat-count=10
commit 19c5f19d69bb5f520fa7213239490c55de06d99d (HEAD)
Merge: 3eff420 4db539b
Author: Kay Sievers <kay.sievers@vrfy.org>
Date:   Tue Apr 3 21:08:04 2012 +0200

    import udev repository

 src/udev/.gitignore  |   40 +
 src/udev/.vimrc      |    4 +
 src/udev/COPYING     |  339 +++
 src/udev/ChangeLog   | 6387 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/udev/INSTALL     |   44 +
 src/udev/Makefile.am |  712 ++++++
 src/udev/NEWS        | 1735 ++++++++++++++
 src/udev/README      |  101 +
 src/udev/TODO        |   22 +
 src/udev/autogen.sh  |   44 +
 ...
 209 files changed, 208701 insertions(+)

ie. only the change to the main repository, as if the everything was added in this commit.

Also, --follow doesn't really follow:

% git log --oneline --follow -- src/udev/src/udevd.c 3e21478 move imported udev into place

[src/udev/src/udevd.c is the new path]

% git log --oneline --follow -- src/udevd.c 4309599 warn about deprecated RUN+="socket:" use e64fae5 udevd: kill hanging event processes after 30 seconds 912541b tabs are as useful as a hole in the head ad29a9f merge udev/, libudev/, systemd/ files in src/; move extras/ to src/ ...

[src/udev/src/udevd.c is the original path]

Is there a way to follow the history also in the subtree?

Thanks, Zbyszek

[1] http://lwn.net/Articles/490413/ [2] http://cgit.freedesktop.org/systemd/systemd/commit/src/udev?id=19c5f19