circular dependency ffmpeg<->x264 - broken pkgng database???

[Bengt Ahlgren]

I build and update my ports using portmaster on 9.1-REL with pkgng
enabled, and create a repo with pkg create -a and pkg repo.

One of my client machines upgrading ports from that repo suddenly
complained about a lot of unresolved dependencies and refused to
upgrade.  Of the long list of unresolved dependencies, these two,
circular, stand out:

multimedia/x264: multimedia/ffmpeg
multimedia/ffmpeg: multimedia/x264

Strange...  Checking the build machine, x264 seems to have a bogus
dependency on ffmpeg:

# pkg info -d x264
x264-0.136.2358_3:
        gpac-libgpac-0.5.0,1
        ffmpeg-2.1.1_1,1

The complaining client has this instead, which I believe is correct:

#  pkg info -d x264
x264-0.136.2358_1:
        gpac-libgpac-0.5.0,1
        png-1.5.17
        jpeg-8_4

I tried rebuilding multimedia/x264, but there was no change, despite
that the the ports tree seems ok:

# make -C /usr/ports/multimedia/x264 run-depends-list
/usr/ports/multimedia/gpac-libgpac

The client was upgraded the last time on Jan 11, so I guess that the
problem appeared after that date.  How come the incorrect (circular)
dependency gets created?  How can I fix this?

Pkg version is:

# pkg -v
1.2.6

The build machine has a ports tree updated with portsnap on Feb 14 at
about 21:16 CET (UTC+1).

Bengt