crossfade goes into infinite loop in new versions of ffmpeg

[Viktors Berstis]

Summary of the bug: Newer version of ffmpeg go into an infinite loop trying to cross-fade two videos. Version ffmpeg-20161122-d316b21-win64-static is the last version I have which works ok. New versions such as ffmpeg-20171031-88c7aa1-win64-static or ffmpeg-3.4-win64-static fail.
The input video can be pretty much anything. I extracted 3 seconds which demos the problem with the ffmpeg command. The result fade.m2g should look the same as either head.m2t or tail.m2t.
How to reproduce:
copy tail.m2t head.m2t
ffmpeg -y -i tail.m2t -i head.m2t -an -filter_complex "[0:v]trim=start=0:end=1,setpts=PTS-STARTPTS[firstclip];[1:v]trim=start=2:end=3,setpts=PTS-STARTPTS[secondclip];[0:v]trim=start=1:end=2,setpts=PTS-STARTPTS[fadeoutsrc];[1:v]trim=start=1:end=2,setpts=PTS-STARTPTS[fadeinsrc];[fadeinsrc]format=pix_fmts=yuva420p,fade=t=in:st=0:d=1:alpha=1[fadein];[fadeoutsrc]format=pix_fmts=yuva420p,fade=t=out:st=0:d=1:alpha=1[fadeout];[fadein]fifo[fadeinfifo];[fadeout]fifo[fadeoutfifo];[fadeoutfifo][fadeinfifo]overlay[crossfade];[firstclip][crossfade][secondclip]concat=n=3[output];[0:a][1:a] acrossfade=d=3 [audio]" -map "[output]" -map "[audio]" fade.m2t -report

[Viktors Berstis]

sample input file

[Viktors Berstis]

log file... four ctrl-c's gets it to exit

[Carl Eugen Hoyos]

Looks like a regression since 02aa0701ae0dc2def8db640c9e3c06dc1b5de70c

[Elon Musk]

Does this still happens with latest master?

[bobe]

Replying to richardpl:

Does this still happens with latest master?

I still see the issue as of 20180117-1b5d3c0

[Elon Musk]

Please try latest version.

[Carl Eugen Hoyos]

Fixed by Paul in 8088b5d69c51b9329ccbc6d1125cf55c54ff6374