firefox 51.1 instability with libvpx 1.6.2

[Paul Goyette <paul%whooppee.com@localhost>]

With pkgsrc updated to just a few hours ago, and all packages rebuilt 
from source and from scratch, I am seeing some serious instability in 
firefox-51.1 with libvpx-1.6.2 and ffmpeg3-3.2.2nb1 (which was "version 
bumped" for libvpx).

In particular, if I visit finance.yahoo.com and just wait, firefox 
will generally core-dump within 15-20 seconds (sometimes even faster).

Reverting libvpx to -1.6.1 and ffmpeg3 to -3.2.2, firefox-50.0.1 things 
are reasonably stable.  Firefox still dumps core occassionally, but not 
quickly and not continuously.  (I have not tested whether firefox 51.0 
will even build with the older versions of libvpx and ffmpeg3, let alone 
tried to run that way.)

All of this is on a NetBSD 7.99.53 amd64 system.



+------------------+--------------------------+------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:      |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org |
+------------------+--------------------------+------------------------+