Popen() list-arg pager process without shell=True

When the first argument to subprocess.Popen is a list, setting
shell=True causes elements of the list to be discarded on POSIX
platforms.

Setting shell=False (the default) causes Popen() to invoke the first
argument of the list and pass the rest of the arguments using
"os.execvpe()-like behavior to execute the child program", per the
subprocess docs at

 * https://docs.python.org/3/library/subprocess.html

Author: rolandwalker

CHANGES.rst

@@ -25,6 +25,7 @@ Unreleased
 -   Properly forward exception information to resources registered with
     ``click.core.Context.with_resource()``. :issue:`2447` :pr:`3058`
 -   Fix regression related to EOF handling in CliRunner. :issue:`2939`:pr:`2940`
+-   Don't discard pager arguments. :issue:`3039` :pr:`3055`
 
 Version 8.2.2
 -------------

src/click/_termui_impl.py

@@ -450,7 +450,7 @@ def _pipepager(
 
     c = subprocess.Popen(
         [str(cmd_path)] + cmd_params,
-        shell=True,
+        shell=False,
         stdin=subprocess.PIPE,
         env=env,
         errors="replace",