problem solved

[ikiwiki] / doc / bugs / UTF-8_BOM_showing_up_inside_a_page__63__.mdwn

I have a git-backed ikiwiki install, and when I commit and push a file from an x86 host (LANG=en_US.UTF-8) to the Ikiwiki box, which is Debian GNU/Linux on Sparc, I sometimes get unusual characters (ef bb ff) before the first character of the wiki text.  It seems that this is a UTF-8 "byte order mark" that is getting inserted automatically into the .wiki file by my editor: http://vim.wikia.com/wiki/VimTip246#Tip:_.23246_-_Working_with_Unicode 

Example:

        http://monkey.linuxworld.com/lwce-2007/

Is there any way for ikiwiki to spot when .wiki files have this BOM and
deal with it, or should I make sure to strip it out before committing?

> It would be easy to make ikiwiki strip out the BOM. For example, a simple
> plugin could be written to s/// them out as a filter.
>
> I'm unsure if ikiwiki should do this by default. --[[Joey]]

> Looked at this some more. It seems this would be a browser bug, after
> all, it's not displaying the BOM properly.
> To test, I've added a BOM to this file. 
> 
> Well, this page looks ok in epiphany and w3m, even with the BOM. Epiphany
> incorrectly displays it as a space (not zero-width). In w3m in a unicode
> xterm, it's invisible. What's going on is that <FEFF> is only a BOM at
> the very beginning of the file. Otherwise, it should be treated as a
> zero-width, non-breaking space. Ie, invisible. Any browsers that display
> it otherwise seem to be broken. 
> 
> I'm having a hard time with the idea that any program that reads utf-8
> data from a file and sticks it in the middle on another, output, utf-8
> file, is broken if it doesn't strip the BOM. It could be argued that
> programs should do that; it could be argued that perl should strip the
> BOM from the beginning of a file whenever reading a file in utf8 mode, to
> avoid all perl programs needing to do this on their own. Or it could be
> argued that requiring all programs do this is silly, and that the BOM was
> designed so you didn't need to strip it.
> 
> After consideration, I prefer this last argument, so I prefer not to
> make ikiwiki stip utf8 BOMS. Calling this bug [[done]].
> 
> --[[Joey]]