bpo-40767: Allow pure Wayland to get default XDG web browser (GH-20382)

Author: jtheoof

Lib/webbrowser.py

@@ -545,7 +545,7 @@ def register_standard_browsers():
                 register(browser, None, BackgroundBrowser(browser))
     else:
         # Prefer X browsers if present
-        if os.environ.get("DISPLAY"):
+        if os.environ.get("DISPLAY") or os.environ.get("WAYLAND_DISPLAY"):
             try:
                 cmd = "xdg-settings get default-web-browser".split()
                 raw_result = subprocess.check_output(cmd, stderr=subprocess.DEVNULL)

Misc/NEWS.d/next/Library/2020-05-27-21-27-01.bpo-40767.L5MnVV.rst

@@ -0,0 +1,3 @@
+:mod:`webbrowser` now properly finds the default browser in pure Wayland
+systems by checking the WAYLAND_DISPLAY environment variable. Patch
+contributed by Jérémy Attali.