Flood doesn't handle the "fault" tag in the XMLRPC response body

[wheelerlaw]

Type: Bug Report

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Your Environment

• Version used:
  • Commit sha: 79fb000
• Environment name and version:
  • Node.js version: 10.16.3
  • npm version 6.9.0
  • Web browser Firefox 68.0
• Operating System and version:
  • Fedora 29, Linux 5.2.7

Summary

So when one submits a .torrent file that exceeds the XMLRPC filesize limits, rtorrent returns a response that includes a <fault>...</fault> block. The rtorrentDeserializer doesn't handle this block and throws an exception, swallowing the original error message.

Example response:

 Status: 200 OK
Content-Type: text/xml
Content-Length: 372

<?xml version="1.0" encoding="UTF-8"?>
<methodResponse>
<fault>
<value><struct>
<member><name>faultCode</name>
<value><i4>-503</i4></value></member>
<member><name>faultString</name>
<value><string>Call XML not a proper XML-RPC call.  XML-RPC request too large.  Max allowed is 524288 bytes</string></value></member>
</struct></value>
</fault>
</methodResponse>

Expected Behavior

It would be nice for the original error message from the <fault>...</fault> block be passed onto the client.

Current Behavior

The rtorrentDeserializer doesn't handle fault block, and returns an exception and swallows the original error message and fault code returned from rtorrent.

This results on the add files button to keep spinning and spinning.

Possible Solution

See PR: #841

Steps to Reproduce

Assuming a working setup of rtorrent and Flood (and rtorrent with the default XMLRPC filesize limits—524288 bytes on the latest master), try to upload a torrent that is larger than that size.

Context