Preserving non breaking spaces in HTML export (maybe other?)

[Étienne Deparis]

Hi,

If I’m not wrong, I think I just came across a little issue while 
using
HTML export in org mode.
As a french writer, we use a lot of non-breaking spaces¹ in 
various
situation. For exemple before double column or question mark:

   Ceci est un exemple :

   N’est-il pas interessant ?

¹ https://en.wikipedia.org/wiki/Non-breaking_space

Above I use a "narrow no-breaking space", but historically other 
might
have used plain non-breaking space ( ).

However, after export all those spaces have disapeared. I cannot 
find
where in the code this replacement is made, thus if one know 
better how
the exporter run here, it would be great to share. It would let me 
try
to work around this.

By order of preference, I’d have expected:

- spaces to be replaced by their HTML entity (either   or 
  )
- spaces left as this (no replacement).

I’m also curious about the rational behind the replacement. Is 
this to
protect something?

Thank you very much for your help,

Étienne