Changes have been made in Git for this ticket:

Ticket #8384: Move all javascript files to the js/ directory

  create mode 100644 imp/js/src/mailbox-dimp.js
  delete mode 100644 imp/templates/javascript/mailbox-dimp.js
http://git.horde.org/diff.php/imp/config/hooks.php.dist?rt=horde-git&r1=78fd3f9eaf63e8d7c79a458a73e2a14a3ae7ca97&r2=0fe99cd692e9cb0d30f8c05b1439207d1b01cd8d
http://git.horde.org/diff.php/imp/index-dimp.php?rt=horde-git&r1=b47e77f6894b29e755b1c9ed51bf8f63278ba101&r2=0fe99cd692e9cb0d30f8c05b1439207d1b01cd8d
http://git.horde.org/co.php/imp/js/src/mailbox-dimp.js?rt=horde-git&r=0fe99cd692e9cb0d30f8c05b1439207d1b01cd8d
http://git.horde.org/diff.php/imp/lib/IMP.php?rt=horde-git&r1=f75d5434dc25fe8a8bd9a4856e9eaa045a88fd75&r2=0fe99cd692e9cb0d30f8c05b1439207d1b01cd8d
http://git.horde.org/diff.php/imp/templates/javascript/mailbox-dimp.js?rt=horde-git&r1=01412d1529aff443f080321abed929825c533bf4&r2=0fe99cd692e9cb0d30f8c05b1439207d1b01cd8d

Yes, this is correct.  I'm just going to go ahead and move the file 
into the js/ directory instead.

Tracked it down to the fact that the file mailbox-dimp.js is being 
loaded directly out of the templates/ directory and the default 
.htaccess file that lives in */templates has a 'Deny from all' rule, 
so you get a 404 Forbidden error trying to load the file from 
<!--a75c305b1c0a6022--><script> tags.



Perhaps it's working for you because you are using lighttpd without 
any equivelant access rules included in your lighttpd config file?

There was recently a change in how we include the mailbox template 
file - it is no longer passed through javascript.php.  But the change 
works fine here.  Maybe a botched update or possible browser caching 
issue?

Using IMP in dynamic mode, and clicking on a folder, the mailbox view 
starts to load, but never gets populated with email. JS Error shown: 
template is undefined - this.template = template.toString() 
prototype.js line 687.



Basic digging found that this.message_list_template is undefined in 
DimpBase.js