_arguments trips on dog

[Mikael Magnusson <mikachu@xxxxxxxxx>]

I've used compdef _gnu_generic dog (among other commands) for some
time, but I suppose I recently updated dog and now, dog<tab> produces
this error:
_arguments:comparguments:327: invalid option definition:
-w[cols][print first 'cols' characters of each line (default=80)]

which is due to this line in dog --help output:
 -w[cols]               print first 'cols' characters of each line (default=80)

it looks like _arguments tries to handle things like -foo[=VALUE], but
the expected input here is -w10 or -w , not -w=10. Any takers? I took
a look at the code but I was nonplussed. I suppose it's somewhere
around line 245 or thereabouts. At the least, it would be nice to just
ignore it and still produce the rest of the completion, instead of
dumping errors in the terminal.

-- 
Mikael Magnusson