I suspect that staging.log is playing tricks on you, but having a blank line at the end of the file. You can always check if the contents of the current instance of $line is empty before you assign it to $newline.

Something like this:

if( $line =~ /^\s*$/ ) {
  $newline = "Blank line.";
} else {
  $newline = $line;
}
[download]

Or, better yet, you could play around with debug mode and step through the program as it runs.

elbieelbieelbie