hide subject if there is just one

I prefer that we not use the subject at all this way.

What should be a drop down list must be topic/category, and subject must be manually entered by each user.

For example, category can be "drupal.org web site problem" and subject can be "cannot post a project" or "bad formatting of wide pages".

But, if you are to do it the right way later, it will overwrite that fix that you just provided a patch for.

It will also create more load on others (review patchs, apply patches, ...etc. will happen twice).

So, for patches, do provide many small patches (which are easier to understand and review) , but do not make them cancel each other or change what a previous patch did.