custom_url conversion results in an empty .module file

After a *lot* of prep work clearing out the issue queue and massively improving the code, I'm finally starting to actually port signup.module to D6 (#222217: Port to 6.x). Based on http://boombatower.com/blog/automated-module-conversion I figured I should give deadwood a try. ;)

Sadly, when I first ran it, I was ending up with an empty signup.module file. After a brief dvm() debugging effort, I discovered that the custom_url conversion was clobbering all the output of the file. If I turn off that one conversion, everything basically works. I haven't had a chance to debug it any further, but either something about signup.module's code that the custom_url conversion isn't expecting, or the custom_url conversion itself, is causing the conversion to seriously fail.

I'm using the HEAD copy of deadwood right now:

// $Id: deadwood.conversions.inc,v 1.13 2008/08/25 20:50:48 solotandem Exp $

It should be easy to reproduce this bug using the signup.module's HEAD version. I haven't tried on any other modules, so I don't know if it's just always happening when you enable the custom_url conversion or not...