What's the deal with CodeBlock::Compile and resManager?

This is something I do not understand myself.

Many functions in the engine call resManager::openFileForWrite().
CodeBlock::Compile() is one of them, but it does it differently than the others.

To begin with, when openFileForWrite() is called in compile(), it is passed a NULL filename.
openFileForWrite() checks if the fileName is NULL, and returns false, skipping half of the function. See below:

if (!file)
      return false;      // don't allow storing files in root

Then compile() checks the return of openFileForWrite() and if it's false, it also returns false and a ton of code beneath that point is never run.

if(!ResourceManager->openFileForWrite(st, codeFileName)) 
      return false;

In particular, I'm curious to the comment in the first codeblock. I know the if clause prevents files from being written to the root, but if you change it to this:

if (!file)
   {
       file = path;
       dStrcpy (path, "");
       //return false;
   }

Which allows files to be written to the root, compile() breaks.

Anyone got a clue?