[TYPO3-dev] Weird Error message with T3X Import when extra NL after closing PHP-Tag: MD5 mismatch

[Stefan Geith]

Hi Devs,

after importing (on another typo3-installation) a new version of one of 
my plugins, I got this error-message in extension-manager:

<snip>
Extension Manager
Wrong file format. No data recognized, Error: MD5 mismatch. Maybe the 
extension file was downloaded and saved as a text file by the browser 
and thereby corrupted!? (Always select "All" filetype when saving 
extensions)
</snip>

After some reserach, I found one php-file in my plugin, that had extra 
newlines after closing php tag ...
I removed these, exported T3X again ... and:

No more error-message after extension import ...

Question:
How can extra newlines after a closing php-tag lead to such a 
missleading error-message ?
Any ideas ? I'm just curious ...

-

Stefan