Two fixes:
Two fixes:

* increment pointer properly on error in extc_mb()

* if conversions functions fail, also reset errno, because they set this.

Fixes the getDirectoryContents bug reported by Ian Lynagh.

FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs