'Process a diff header line.'

def process_header(self):

    if self.line.startswith('Binary    files    '):
        self.file.binary = True
    elif (self.line == '---    /dev/null'):
        self.file.old.exists = False
    elif (self.line == '+++    /dev/null'):
        self.file.new.exists = False
    else:
        self.file.append_header(self.line)
