Abetterrouteplanner.com doesn't display anything in Firefox if geo.enabled==false

🚧 THIS IS A TICKET MIGRATED FROM UPVOTY. The original ticket and comments will be available for a limited time over at:
https://abrp.upvoty.com/b/report-a-bug/abetterrouteplannercom-doesnt-display-anything-in-firefox-if-geoenabledfalse/
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The ABPR website's JS code makes the false assumption that Navigator.geolocation is always present. It's not and that's OK.
If the "geo.enabled" (hidden) setting in Firefox is set to "false", then Navigator.geolocation does not exist.

The JS code should be handling this situation gracefully the same way, when Navigator.geolocation exists, but permission is not granted by the user to share location data.