General: Correct path replacement regex in `wp_guess_url`.

In `wp_guess_url`, the regex to check for wp-login.php in the URL is slightly too permissive, not escaping `.` in "wp-login.php".  `.` is a token in regex that matches any character.

This change simply escapes the `.` and adds unit test coverage for `wp_guess_url`.

Props cfinke, ocean90, jrf, voldemortensen, jdgrimes, curdin, netweb, petitphp, SergeyBiryukov, costdev.
Fixes #36827.
Built from https://develop.svn.wordpress.org/trunk@54146


git-svn-id: http://core.svn.wordpress.org/trunk@53705 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/functions.php

@@ -6033,7 +6033,7 @@ function wp_guess_url() {
 
 		// The request is for the admin.
 		if ( strpos( $_SERVER['REQUEST_URI'], 'wp-admin' ) !== false || strpos( $_SERVER['REQUEST_URI'], 'wp-login.php' ) !== false ) {
-			$path = preg_replace( '#/(wp-admin/.*|wp-login.php)#i', '', $_SERVER['REQUEST_URI'] );
+			$path = preg_replace( '#/(wp-admin/?.*|wp-login\.php.*)#i', '', $_SERVER['REQUEST_URI'] );
 
 			// The request is for a file in ABSPATH.
 		} elseif ( $script_filename_dir . '/' === $abspath_fix ) {

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-alpha-54145';
+$wp_version = '6.1-alpha-54146';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.