When URL_PATH is blank, it should assume that it is '/'

[ibatten]

Describe the bug

Consider a configuration where nginx is set up with:

server {
...
server_name cacti.dom.ain;
...
root /usr/share/cacti/site;
}

Under <= 1.1.38 (I believe) you could do upgrades with $url_path set to ''. It now appears to need '/', and goes badly wrong (extensive attempts to fetch cacti.domain/install/install/thing.js, note double install) unless this is corrected.

[[ I have been trying to get onto the 1.2 train for some months, on and off. I finally built a replica system and systematically fixed all the load problems I was seeing with symlinks, until I could get to a stage where it was more obvious what the problem was ]]

To Reproduce

Set url_path to '' in config.php. Attempt to perform an upgrade.

Expected behavior

A better error message, or simply set it to '/' if it is ''.

Screenshots

Desktop (please complete the following information):

Desktop Safari latest or Chrome latest on MacOS. Server is Debian 10 out of the box. I doubt either matters much.

[netniV]

Part of me wonders on the reprocussions of setting it to / when blank if the site is in a subdirectory, such as /cacti/. With the blank, most web-based main folder pages would include based on the current directory of the url which would be right. Making that a / suddenly changes that functionality.

However, I think i am going to implement it since the URL path should ALWAYS be defined to properly identify the root location of the website.

[netniV]

So, I have now changed this to obey the following rules:

• Default to '/cacti/' [existing]
• Allow override from config.php [existing]
• If now blank assume '/' [new]

So, this keeps existing functionality whilst correcting a misconfiguration in the config.php. If no urlpath is defined in the config.php then '/config/' is still retained as the default and as long as you set it, then the path will be used.