Closing Leaflet pop-up in map in a page whose html head contains <base target="_blank"/> opens new map page

[eggertj]

• I've looked at the documentation to make sure the behavior is documented and expected
• I'm sure this is a Leaflet code issue, not an issue with my own code nor with the framework I'm using (Cordova, Ionic, Angular, React…)
• I've searched through the issues to make sure it's not yet reported

Steps to reproduce
Steps to reproduce the behavior:

• Make an html page with this in the element:
  
• Embed a Leaflet-based map with marker popups in that page
• Open the page in a browser
• Open a popup (if not already open)
• Close the popup using the x in the popup

Expected behavior

I expect the popup to close and nothing else to happen.

Current behavior

The popup closes, but a new page also opens with the same URL but with the suffix #close.

Environment

• Leaflet version: 1.8.0
• Browser (with version): Safari 15.4 (17613.1.17.1.13)
• User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.4 Safari/605.1.15
• OS/Platform (with version): macOS Monterey 12.3.1 (21E258)

Also tested on same platform with

• Browser: Firefox 99.0.1 (64-bit)

Additional context

This didn't happen with LeafletJS 1.7.1.

Minimal example reproducing the issue

Please create an example using https://leafletjs.com/edit.html or any other jsfiddle-like site.

• this example is as simple as possible
• this example does not rely on any third party code
  See
  https://www.aegilops.com/pedigreemv5b.html

Compare with same page with Leaflet 1.7.1:
https://www.aegilops.com/pedigreem.html

[IvanSanchez]

Duplicate of #8159