[WebUI] Add test for torrent files containing md5sums

Some torrent files built with py3createtorrent fail to produce a
file listing in the WebUI when uploading them.
This made it impossible to add such files.
Specifically this is caused by the additional metadata when using
py3createtorrent with the `--md5` flag.

deluge/tests/data/md5sum.torrent

@@ -0,0 +1 @@
+d8:announce25:lol.this.is.not.a.tracker7:comment36:created with py3createtorrent v0.9.610:created by23:py3createtorrent v0.9.613:creation datei1590076175e4:infod5:filesld6:lengthi4e6:md5sum32:59bcc3ad6775562f845953cf016242254:pathl3:loleed6:lengthi5e6:md5sum32:10245815f893d79f3d779690774f0b434:pathl4:rofleee4:name4:test12:piece lengthi16384e6:pieces20:û8éß6A¢Ú²ú-Y>+S]\/ßee

deluge/tests/test_web_api.py

@@ -9,6 +9,7 @@
 
 from __future__ import unicode_literals
 
+import json
 from io import BytesIO
 
 from twisted.internet import defer, reactor
@@ -130,6 +131,16 @@ class WebAPITestCase(WebServerTestBase):
         self.assertEqual(ret['info_hash'], 'ab570cdd5a17ea1b61e970bb72047de141bce173')
         self.assertTrue('files_tree' in ret)
 
+    def test_get_torrent_info_with_md5(self):
+        filename = common.get_test_data_file('md5sum.torrent')
+        ret = self.deluge_web.web_api.get_torrent_info(filename)
+        # JSON dumping happens during response creation in normal usage
+        # JSON serialization may fail if any of the dictionary items are byte arrays rather than strings
+        ret = json.loads(json.dumps(ret))
+        self.assertEqual(ret['name'], 'test')
+        self.assertEqual(ret['info_hash'], 'f6408ba9944cf9fe01b547b28f336b3ee6ec32c5')
+        self.assertTrue('files_tree' in ret)
+
     def test_get_magnet_info(self):
         ret = self.deluge_web.web_api.get_magnet_info(
             'magnet:?xt=urn:btih:SU5225URMTUEQLDXQWRB2EQWN6KLTYKN'