Found using fuzzing. Reproduction with pathoc, given "mitmproxy -s" and
pathod running on 9999:
get:'http://localhost:9999/p/':s'200:b\'foo\':h\'Content-Length\'=\'3\'':i58,'\x1a':r
return flow.FlowMaster.run(self)
File "/Users/aldo/mitmproxy/mitmproxy/libmproxy/controller.py", line 111, in run
self.tick(self.masterq, 0.01)
File "/Users/aldo/mitmproxy/mitmproxy/libmproxy/flow.py", line 613, in tick
return controller.Master.tick(self, q, timeout)
File "/Users/aldo/mitmproxy/mitmproxy/libmproxy/controller.py", line 101, in tick
self.handle(*msg)
File "/Users/aldo/mitmproxy/mitmproxy/libmproxy/controller.py", line 118, in handle
m(obj)
File "/Users/aldo/mitmproxy/mitmproxy/libmproxy/flow.py", line 738, in handle_responseheaders
self.stream_large_bodies.run(f, False)
File "/Users/aldo/mitmproxy/mitmproxy/libmproxy/flow.py", line 155, in run
r.headers, is_request, flow.request.method, code
File "/Users/aldo/mitmproxy/mitmproxy/netlib/http.py", line 401, in expected_http_body_size
raise HttpError(400 if is_request else 502, "Invalid content-length header: %s" % headers["content-length"])
netlib.http.HttpError: Invalid content-length header: ['\x1a3']
