Directory separator for INFO_JS_DIR

[Gavin Smith]

On Sun, Oct 23, 2022 at 04:47:50PM +0200, pertusus@free.fr wrote:
> 
> I tracked it down to tp/ext/epub3.pm and there is actually already a
> FIXME, I knew that something like that was bound to happen:
> 
>     # FIXME INFO_JS_DIR is used both as a filesystem directory name
>     # and as path in document, as a path in document '../' should be
>     # used whatever File::Spec->updir() is.
> 
> To me the basic issue is that INFO_JS_DIR is used, in HTML.pm in
> output(), both as an HTML path l 8941 and to copy local files near l
> 10184 of HTML.pm.  As a local file path, it would make sense to
> use backward slash, but not as HTML path.

In HTML.pm, File::Copy is used to copy the files.  It's possible
that forward slashes would work on all relevant OS's, in which case
we can hard-code a forward slash in ext/epub3.pm.  I believe that
forward slashes work in most places on MS-Windows as a directory
separator, except on the command line.

Does it even make sense to use INFO_JS_DIR for EPUB output?  Do EPUB
readers do anything with the JavaScript files?