Fixed error when a file was removed from filesystem. Fixed #1120.

CHANGELOG

@@ -8,6 +8,8 @@ Version 1.5.1 (unreleased)
 ==========================
 [https://github.com/OpenSlides/OpenSlides/issues?milestone=15]
 
+Files:
+- Fixed error when a file was removed from filesystem.
 Other:
 - Fixed http status code when requesting a non-existing static page using
   Tordado web server.

openslides/mediafile/models.py

@@ -4,6 +4,7 @@ import mimetypes
 
 from django.core.urlresolvers import reverse
 from django.db import models
+from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy, ugettext_noop
 
 from openslides.projector.models import SlideMixin
@@ -80,15 +81,20 @@ class Mediafile(SlideMixin, models.Model):
 
     def get_filesize(self):
         """
-        Transforms Bytes to Kilobytes or Megabytes. Returns the size as string.
+        Transforms bytes to kilobytes or megabytes. Returns the size as string.
         """
         # TODO: Read http://stackoverflow.com/a/1094933 and think about it.
+        try:
             size = self.mediafile.size
+        except OSError:
+            size_string = _('unknown')
+        else:
             if size < 1024:
-            return '< 1 kB'
+                size_string = '< 1 kB'
-        if size >= 1024 * 1024:
+            elif size >= 1024 * 1024:
                 mB = size / 1024 / 1024
-            return '%d MB' % mB
+                size_string = '%d MB' % mB
             else:
                 kB = size / 1024
-            return '%d kB' % kB
+                size_string = '%d kB' % kB
+        return size_string

openslides/mediafile/templates/mediafile/mediafile_list.html

@@ -27,7 +27,7 @@
         {% for mediafile in mediafile_list %}
         <tr class="{% if mediafile.is_active_slide %}activeline{% endif %}">
             <td><a href="{{ mediafile.mediafile.url }}">{{ mediafile }}</a></td>
-            <td>{{ mediafile.filetype }}</td>
+            <td>{% trans mediafile.filetype %}</td>
             <td>{{ mediafile.get_filesize }}</td>
             <td>{{ mediafile.timestamp }}</td>
             <td><a href="{{ mediafile.uploader|absolute_url }}">{{ mediafile.uploader }}</a></td>

tests/mediafile/tests.py

@@ -195,4 +195,5 @@ class MediafileTest(TestCase):
             bigfile.seek(1048575)
             bigfile.write('0')
         self.assertEqual(object_4.get_filesize(), '1 MB')
-        object_4.mediafile.delete()
+        os.remove(mediafile_4_path)
+        self.assertEqual(object_4.get_filesize(), 'unknown')