[FFmpeg-user] on acodec copy : "codec frame size not set"

[Sean Darcy]

Using today's git:

ffmpeg -f concat -i mylist.txt -codec:v libx264 -crf 35 -codec:a copy 
test3.mp4
.................
[mp4 @ 0x211cb20] track 1: codec frame size is not set
Output #0, mp4, to 'test3.mp4':
   Metadata:
     encoder         : Lavf55.14.101
     Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), 
yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 30k tbn, 29.97 tbc
     Stream #0:1: Audio: ac3 ([165][0][0][0] / 0x00A5), 48000 Hz, 
stereo, 256 kb/s
Stream mapping:
   Stream #0:0 -> #0:0 (h264 -> libx264)
........

This looks like Ticket 1240: regression: "codec frame size is not set" 
using -acodec copy

But now it continues encoding. Should I do something about this warning?

sean