4. We know you're really busy, you have a full work load but please try to remember... "Are you sure you changed the code?"
Summary
Using a Windows editor against an ftp’ed file can lead to unexpected results!
Background
I recently edited a file using FileZilla to make a one line change to undo an erroneous fix to one of my plugins ( oik ). Rather than simply change the line in error, I decided to comment it out using a double slash comment then add the replacement line.
// $args['ID'] = $post_id;
$args['post_parent'] = $post_id;
It looked like I’d made the right change. But it wasn’t fixing the problem. The same code change was working locally, but it wasn’t making any difference on the real website.
I thought that perhaps there was some other change that I’d made locally which wasn’t duplicated on the server. So I extracted the code and ran a file compare. Then it became obvious.
expected source verses unexpected two line double slash comment
I thought I’d edited the file to create a single double slash comment for the original line and added a new line. But I hadn’t noticed that the file I was editing had Unix line endings, so the new line wasn’t really a new line. Had I simply changed the original line this problem would not have occurred.
Reproducing the problem
Having fixed the problem I edited the file again. This time the Unix line endings had been fixed. So I reproduced the problem in another file.
- Choose a file in FileZilla
- Select View/Edit
- Change the file
- Save to the server
- Edit the file in WordPress plugin editor – to show it’s not right
- Edit the file again using FileZilla
editing a unix line ending file in Windows
editing in the plugin editor
re-editing the unix file in Windows – CRLF OK now
Moral of the story
Check that the code change that you made is really the change you intended to make.