.htaccess mod-rewrite url-rewriting prestashop trailing-slash

Prestashop not redirecting to correct language if missing a trailing slash (i.e. domain.com/fr)

How can I force prestashop to add a trailing slash to the language in the URL if there isn´t one? For example these links work fine to take you to the correct language:

http://petiteannee.ch/en/
http://petiteannee.ch/fr/
http://petiteannee.ch/de/

but these do not:

http://petiteannee.ch/en
http://petiteannee.ch/fr
http://petiteannee.ch/de

How can I fix this as it is causing me increased bounce rates?

My .htaccess file is this:

ErrorDocument 404 '/index.php?controller=404'
ErrorDocument 404 '/index.php?controller=404'

RequestHeader unset Accept-Language
# ~~start~~ Do not remove this comment, Prestashop will keep automatically the code outside this comment when .htaccess will be generated again
# .htaccess automaticaly generated by PrestaShop e-commerce open-source solution
# http://www.prestashop.com - http://www.prestashop.com/forums

<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule . - [E=REWRITEBASE:/]
RewriteRule ^api/?(.*)$ %{ENV:REWRITEBASE}webservice/dispatcher.php?url=$1 [QSA,L]
# Images
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$1$2$3$4.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$1$2$3$4$5.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$1$2$3$4$5$6.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$1$2$3$4$5$6$7.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$1$2$3$4$5$6$7$8.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$1$2$3$4$5$6$7$8$9.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$8/$1$2$3$4$5$6$7$8$9$10.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^c/([0-9]+)(\-[\.*_a-zA-Z0-9-]*)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^c/([a-zA-Z_-]+)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2.jpg [L]
# AlphaImageLoader for IE and fancybox
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^images_ie/?([^/]+)\.(jpe?g|png|gif)$ js/jquery/plugins/fancybox/images/$1.$2 [L]

# Dispatcher
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^.*$ - [NC,L]
RewriteCond %{HTTP_HOST} ^petiteannee.ch$
RewriteRule ^.*$ %{ENV:REWRITEBASE}index.php [NC,L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule . - [E=REWRITEBASE:/]
RewriteRule ^api/?(.*)$ %{ENV:REWRITEBASE}webservice/dispatcher.php?url=$1 [QSA,L]

# Images
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$1$2$3$4.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$1$2$3$4$5.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$1$2$3$4$5$6.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$1$2$3$4$5$6$7.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$1$2$3$4$5$6$7$8.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$1$2$3$4$5$6$7$8$9.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$8/$1$2$3$4$5$6$7$8$9$10.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^c/([0-9]+)(\-[\.*_a-zA-Z0-9-]*)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^c/([a-zA-Z_-]+)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2.jpg [L]
# AlphaImageLoader for IE and fancybox
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^images_ie/?([^/]+)\.(jpe?g|png|gif)$ js/jquery/plugins/fancybox/images/$1.$2 [L]

# Dispatcher
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^.*$ - [NC,L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.ch$
RewriteRule ^.*$ %{ENV:REWRITEBASE}index.php [NC,L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule . - [E=REWRITEBASE:/]
RewriteRule ^api/?(.*)$ %{ENV:REWRITEBASE}webservice/dispatcher.php?url=$1 [QSA,L]

# Images
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$1$2$3$4.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$1$2$3$4$5.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$1$2$3$4$5$6.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$1$2$3$4$5$6$7.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$1$2$3$4$5$6$7$8.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$1$2$3$4$5$6$7$8$9.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$8/$1$2$3$4$5$6$7$8$9$10.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^c/([0-9]+)(\-[\.*_a-zA-Z0-9-]*)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^c/([a-zA-Z_-]+)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2.jpg [L]
# AlphaImageLoader for IE and fancybox
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^images_ie/?([^/]+)\.(jpe?g|png|gif)$ js/jquery/plugins/fancybox/images/$1.$2 [L]

# Dispatcher
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^.*$ - [NC,L]
RewriteCond %{HTTP_HOST} ^petiteannee.com$
RewriteRule ^.*$ %{ENV:REWRITEBASE}index.php [NC,L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule . - [E=REWRITEBASE:/]
RewriteRule ^api/?(.*)$ %{ENV:REWRITEBASE}webservice/dispatcher.php?url=$1 [QSA,L]

# Images
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$1$2$3$4.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$1$2$3$4$5.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$1$2$3$4$5$6.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$1$2$3$4$5$6$7.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$1$2$3$4$5$6$7$8.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$1$2$3$4$5$6$7$8$9.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])([0-9])(\-[_a-zA-Z0-9-]*)?(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/p/$1/$2/$3/$4/$5/$6/$7/$8/$1$2$3$4$5$6$7$8$9$10.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^c/([0-9]+)(\-[\.*_a-zA-Z0-9-]*)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2$3.jpg [L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^c/([a-zA-Z_-]+)(-[0-9]+)?/.+\.jpg$ %{ENV:REWRITEBASE}img/c/$1$2.jpg [L]
# AlphaImageLoader for IE and fancybox
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^images_ie/?([^/]+)\.(jpe?g|png|gif)$ js/jquery/plugins/fancybox/images/$1.$2 [L]

# Dispatcher
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^.*$ - [NC,L]
RewriteCond %{HTTP_HOST} ^www.petiteannee.com$
RewriteRule ^.*$ %{ENV:REWRITEBASE}index.php [NC,L]
</IfModule>

#If rewrite mod isn't enabled

# ~~end~~ Do not remove this comment, Prestashop will keep automatically the code outside this comment when .htaccess will be generated again

#@__HCP_END__@#
# Anything after the comment above is left alone

Many thanks

Solution

Right before # Images in your htaccess file, add:

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([a-z]{2})$ /$1/ [L,R=301]