ffrtmp errors where librtmp succeeds

[RiCON]

Summary of the bug:
Opening the same stream with FFmpeg compiled with native rtmp support fails and succeeds if compiled with librtmp

How to reproduce:
FFmpeg with librtmp:

% ffmpeg-librtmp.exe -rtmp_swfverify http://www.hitbox.tv/static/player/flowplayer/flowplayer.commercial-3.2.16.swf -i rtmp://edge.live.hitbox.tv/live/csgobattle
ffmpeg version N-79975-g97946b2 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.3.0 (Rev5, Built by MSYS2 project)
  configuration:  --enable-libx264 --enable-libvpx --enable-libopus --disable-postproc --disable-doc --disable-demuxer=asf --disable-ffplay --enable-librtmp --enable-openssl --enable-gpl --enable-nonfree --disable-debug
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 41.102 / 57. 41.102
  libavformat    57. 36.100 / 57. 36.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 45.100 /  6. 45.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  0.101 /  2.  0.101
Metadata:
  Server                NGINX RTMP (github.com/arut/nginx-rtmp-module)
  width                 1280.00
  height                720.00
  displayWidth          1280.00
  displayHeight         720.00
  duration              0.00
  framerate             50.00
  fps                   50.00
  videodatarate         2000.00
  videocodecid          0.00
  audiodatarate         160.00
  audiocodecid          16.00
[live_flv @ 000000b3ffd07260] video stream discovered after head already parsed
[live_flv @ 000000b3ffd07260] audio stream discovered after head already parsed
Input #0, live_flv, from 'rtmp://edge.live.hitbox.tv/live/csgobattle':
  Metadata:
    Server          : NGINX RTMP (github.com/arut/nginx-rtmp-module)
    displayWidth    : 1280
    displayHeight   : 720
    fps             : 50
    profile         :
    level           :
  Duration: 00:00:00.00, start: 726683.072000, bitrate: N/A
    Stream #0:0: Video: h264 (Main), yuv420p(tv, bt709/bt709/iec61966-2-1), 1280x720, 50 fps, 50 tbr, 1k tbn
    Stream #0:1: Audio: aac (LC), 48000 Hz, stereo, fltp
At least one output file must be specified

FFmpeg with native rtmp

% ffmpeg-ffrtmp.exe -rtmp_swfverify http://www.hitbox.tv/static/player/flowplayer/flowplayer.commercial-3.2.16.swf -i rtmp://edge.live.hitbox.tv/live/csgobattle
ffmpeg version N-79975-g97946b2 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.3.0 (Rev5, Built by MSYS2 project)
  configuration:  --enable-libx264 --enable-libvpx --enable-libopus --disable-postproc --enable-gcrypt --disable-doc --disable-demuxer=asf --disable-ffplay --enable-gpl --disable-debug
  libavutil      55. 24.100 / 55. 24.100
  libavcodec     57. 41.102 / 57. 41.102
  libavformat    57. 36.100 / 57. 36.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 45.100 /  6. 45.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  0.101 /  2.  0.101
rtmp://edge.live.hitbox.tv/live/csgobattle: I/O error

[RiCON]

As reference, the rtmp_swfsize is 259809 and rtmp_swfhash is 7520eecf7b4f3346254728ab53ad99c4bd800e34c78ccf47553170a0986b88a3.

Using rtmpdump -V confirms these values are correct.
Using the values directly instead of -rtmp_swfverify still triggers the same I/O error in ffrtmp.

[RiCON]

Fixed in ​http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=c0b3781bf2fef529d64af0e36ea84c0a34522367