Problem with Popover "Corner placement" on Firefox 68.0.0

[BogdanPolandUkraine]

Bug description:

On your page with library (https://valor-software.com/ngx-bootstrap/#/popover), popover "Corner placement" doesn't work correct on Mozilla Firefox > 68.0.0.
For example:
when popover is on right side, position of arrow is always on top in "right bottom" and "right top":

In chrome, everything is correct:

ngx-bootstrap: 5.6.2

Angular: 9

Bootstrap: 4.0

[iampranavsethi]

I can also confirm this is not working in Firefox version 90.0b3 (Developer Edition) on the ngx-bootstrap homepage and neither in the local Angular Application. (Works in Chrome)

ngx-bootstrap: v6.2.0
Angular: v9
Bootstrap: v4.3

[iampranavsethi]

When #5027 was merged with #66ae92d
Line No: 47, arrow.ts file
sonicpro@3e3fe8b

const targetBorderRadius = parseFloat(css.borderRadius);  // css.borderRadius is "" in Firefox

this results in targetBorderRadius being set to NaN and essentially the correct value is not set as anything added to NaN is also NaN, I will see if I am able to raise a pull request for this over the weekend but that line is causing it to break. Not sure if the Firefox implementation is at fault or something else.

A quick fix would be to add a fallback value of 0 in case that results in a NaN, so like

const targetBorderRadius = parseFloat(css.borderRadius) || 0; 

Hope this helps anyone else who is facing this issue.