And unfortunately for some, there are those hosts that say: thou has no way as an end user to adjust the document root of the server as public_html is your document root, you have no access to a higher path/area, and if you decide to place the contents of your store in a sub-directory from public_html you will forever be forced to use some other process to ensure that customers arrive at that location as the "root" of your store. And while such individuals have the right to change to a host that would actually allow them to not have a web-facing sub-directory, there are those that will persist on with the domain hosted in sub-directory by way of redirect/continuous display of Web facing sub-directory.

The thing is here. The OP had previously hosted the site with this sub-directory is the domain, continues to want that and the site is not supporting that arrangement and the host has not provided a solution that complies with that arrangement. So... from the OPs perspective the document root has always been public_html with the site provided from catalog as the first directory off of public_html...

As DrByte said, it worked before the host made a change and it was working in such a way that catalog was displayed in the browser as a sub-directory off of the domain name. If you are stating/giving a solution that will alter the uri that has been in existence and used for the site, the effects of such modification both "good" and bad should be explained to the OP. Otherwise, as has been provided give a solution that restores the web-facing operation back to what it was.

Like I said, I didn't see how the document root could be used to necessarily force a visitor onto the web-facing catalog directory by way of entering just the domain name. And no such solution was described as it isn't possible without some form of rewrite/redirect based on the above two posts.

I personally agree that a sub-directory in the uri (DIR_WS_CATALOG) is generally unnecessary if not in some ways harmful, but that is associated with a new install not an existing one of a relatively new store. Making a change at that point in the operation is something that should be planned not just done because a couple of people made it sound cool. :)