`cvs_runcvs` should not take an array reference. It's
usual for this type of function to take a list of parameters
to pass to the command.
+
+> Thanks for reading carefully. I've tested your suggestions and
+> applied them on my branch. --[[schmonz]]
+
+----
+
+I've abstracted out CVS's involvement in the wrapper, adding a new
+"wrapperargcheck" hook to examine `argc/argv` and return success or
+failure (failure causes the wrapper to terminate) and implementing
+this hook in the plugin. In the non-CVS case, the check immediately
+returns success, so the added overhead is just a function call.
+
+Given how rarely anything should need to reach in and modify the
+wrapper -- I'd go so far as to say we shouldn't make it too easy
+-- I don't think it's worth the effort to try and design a more
+general-purpose way to do so. If and when some other problem thinks
+it wants to be solved by a new wrapper hook, it's easy enough to add
+one. Until then, I'd say it's more important to keep the wrapper as
+short and clear as possible. --[[schmonz]]