Re: [PATCH] gitk: don't highlight files after submodules as submodules

> gitk applies submodule highlighting (coloring lines starting with
> "  >" and "  <") when `currdiffsubmod` is not an empty string.
> However, it fails to reset `currdiffsubmod` after a submodule diff
> ends, so any file diffs following a submodule diff will still be
> highlighted as if they were submodule diffs.
> 
> There are two problems with the way gitk tries to reset `currdiffsubmod`:
> 
> 1. The code says `set $currdiffsubmod` instead of `set currdiffsubmod`,
>    so it actually sets the variable whose name is the submodule path
>    instead.
> 
> 2. It tries to do it after the first line in a submodule diff, which
>    is incorrect, since submodule diffs can contain multiple lines.
> 
> Fix this by resetting `currdiffsubmod` when a file diff starts.
> 
> Signed-off-by: Роман Донченко <dpb@corrigendum.ru>