Broken SVG thumbnail in Assets

Hi,

When I upload an SVG into the Assets app, the thumbnail is broken in two ways:

1. Instead of being a real thumbnail, it is simply a black 150x150 square
2. It is displayed at 150x300 (in Chrome 36/Mac), so it overlaps other parts of the UI

The generated img looks like:

<img src="/files/illustrations/structure-en-w150h150@2x.png" alt="Structure (en/SVG)" class="thumb">

In Chrome Dev Tools, when I hover over the image, it reports that it is "150 x 300 pixels (Natural: 275 x 300 pixels)". I don’t see anywhere in the CSS that’s explicitly setting width/height on the image.

My diagnostics:

Perch: 2.5.4, PHP: 5.5.14, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: bf9ad53b11c9a57efdb1057292d73b928b8c5c77 $, with PDO
Server OS: Linux, apache2handler
Installed apps: content (2.5.4), assets (2.5.4), perch_blog (4.1)
App runtimes: <?php include(PERCH_PATH.'/core/apps/content/runtime.php'); include(PERCH_PATH.'/addons/apps/perch_blog/runtime.php'); ?>
PERCH_LOGINPATH: /perch
PERCH_PATH: /srv/www/vhosts/…/perch
PERCH_CORE: /srv/www/vhosts/…/perch/core
PERCH_RESFILEPATH: /srv/www/vhosts/…/perch/../files
Image manipulation: GD Imagick
PHP limits: Max upload 200M, Max POST 800M, Memory: 256M, Total max file upload: 200M
Resource folder writeable: Yes
HTTP_HOST: …
DOCUMENT_ROOT: /srv/www/vhosts/…
REQUEST_URI: /perch/core/settings/diagnostics/
SCRIPT_NAME: /perch/core/settings/diagnostics/index.php

Thanks!