PHP 7.3 Compatibility: Fix compact related notices.

In PHP 7.3, the `compact()` function has been changed to issue an `E_NOTICE` level error if a passed string refers to an unset variable. In previous versions of PHP, this notice was silently skipped. This fixes a few more instances of unset variables in the WordPress admin.

The full RFC can be viewed here: https://wiki.php.net/rfc/compact.

See #44416.
Fixes #45483.
Built from https://develop.svn.wordpress.org/branches/5.0@44185


git-svn-id: http://core.svn.wordpress.org/branches/5.0@44015 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/plugin-install.php

@@ -394,6 +394,7 @@ function install_plugin_install_status($api, $loop = false) {
 	$status = 'install';
 	$url = false;
 	$update_file = false;
+	$version = '';
 
 	/*
 	 * Check to see if this plugin is known to be installed,

wp-admin/includes/post.php

@@ -1029,18 +1029,24 @@ function wp_edit_posts_query( $q = false ) {
 		$post_type = 'post';
 
 	$avail_post_stati = get_available_post_statuses($post_type);
+	$post_status      = '';
+	$perm             = '';
 
 	if ( isset($q['post_status']) && in_array( $q['post_status'], $post_stati ) ) {
 		$post_status = $q['post_status'];
 		$perm = 'readable';
 	}
 
+	$orderby = '';
+
 	if ( isset( $q['orderby'] ) ) {
 		$orderby = $q['orderby'];
 	} elseif ( isset( $q['post_status'] ) && in_array( $q['post_status'], array( 'pending', 'draft' ) ) ) {
 		$orderby = 'modified';
 	}
 
+	$order = '';
+
 	if ( isset( $q['order'] ) ) {
 		$order = $q['order'];
 	} elseif ( isset( $q['post_status'] ) && 'pending' == $q['post_status'] ) {

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0.2-alpha-44183';
+$wp_version = '5.0.2-alpha-44185';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.