Bug in port_version's package version comparisons?

[Conrad J. Sabatier]

I've manually upgraded a few Xorg packages recently to the latest
versions available on the ftp sites.  As a result, portversion is now
giving erroneous results for some packages:

# portversion -v -O -L ='
inputproto-1.4.2            > succeeds port (port has 1.3.2)
libX11-1.1.2                <  needs updating (port has 1.1.1_2,1)
libXi-1.1.0                 <  needs updating (port has 1.0.2,1)
tcl-8.5.a.6_2               >  succeeds port (port has 8.5.a.6_1)
tcl-threads-8.5.a.6_2       >  succeeds port (port has 8.5.a.6_1)
tk-8.5.a.6_3                >  succeeds port (port has 8.5.a.6_2)
tk-threads-8.5.a.6_3        >  succeeds port (port has 8.5.a.6_2)
totem-2.18.1_2              <  needs updating (port has 2.18.2)
xchat-2.8.2_2               >  succeeds port (port has 2.8.2_1)
xf86-input-keyboard-1.2.0   >  succeeds port (port has 1.1.1)
xf86-input-mouse-1.2.1      >  succeeds port (port has 1.1.2)
xf86-video-nv-2.0.96        >  succeeds port (port has 1.2.2.1)

How is it that, e.g, libX11-1.1.2 is considered less than than
1.1.1_2,1?  Or libXi-1.1.0 is less than 1.0.2,1?  This makes no sense
to me at all.

Oddly, the version comparisons on other Xorg packages provide the
expected results.

The most annoying end result of this, of course, is that it's no longer
safe to use 'portupgrade -a', unless I want to "downgrade" these two
packages in the process.  :-(

Any insights on this strange behavior?

-- 
Conrad J. Sabatier <conrads at cox.net>