diff -r 3d4e9c994f10 -r a86126ab1dd4 wp/wp-admin/includes/revision.php
--- a/wp/wp-admin/includes/revision.php	Tue Oct 22 16:11:46 2019 +0200
+++ b/wp/wp-admin/includes/revision.php	Tue Dec 15 13:49:49 2020 +0100
@@ -12,20 +12,21 @@
  *
  * @since 3.6.0
  *
- * @param object|int $post         The post object. Also accepts a post ID.
- * @param int        $compare_from The revision ID to compare from.
- * @param int        $compare_to   The revision ID to come to.
- *
+ * @param WP_Post|int $post         The post object or post ID.
+ * @param int         $compare_from The revision ID to compare from.
+ * @param int         $compare_to   The revision ID to come to.
  * @return array|bool Associative array of a post's revisioned fields and their diffs.
  *                    Or, false on failure.
  */
 function wp_get_revision_ui_diff( $post, $compare_from, $compare_to ) {
-	if ( ! $post = get_post( $post ) ) {
+	$post = get_post( $post );
+	if ( ! $post ) {
 		return false;
 	}
 
 	if ( $compare_from ) {
-		if ( ! $compare_from = get_post( $compare_from ) ) {
+		$compare_from = get_post( $compare_from );
+		if ( ! $compare_from ) {
 			return false;
 		}
 	} else {
@@ -33,7 +34,8 @@
 		$compare_from = false;
 	}
 
-	if ( ! $compare_to = get_post( $compare_to ) ) {
+	$compare_to = get_post( $compare_to );
+	if ( ! $compare_to ) {
 		return false;
 	}
 
@@ -52,7 +54,7 @@
 		$compare_to   = $temp;
 	}
 
-	// Add default title if title field is empty
+	// Add default title if title field is empty.
 	if ( $compare_from && empty( $compare_from->post_title ) ) {
 		$compare_from->post_title = __( '(no title)' );
 	}
@@ -71,11 +73,11 @@
 		 *
 		 * @since 3.6.0
 		 *
-		 * @param string  $compare_from->$field The current revision field to compare to or from.
-		 * @param string  $field                The current revision field.
-		 * @param WP_Post $compare_from         The revision post object to compare to or from.
-		 * @param string  null                  The context of whether the current revision is the old
-		 *                                      or the new one. Values are 'to' or 'from'.
+		 * @param string  $revision_field The current revision field to compare to or from.
+		 * @param string  $field          The current revision field.
+		 * @param WP_Post $compare_from   The revision post object to compare to or from.
+		 * @param string  $context        The context of whether the current revision is the old
+		 *                                or the new one. Values are 'to' or 'from'.
 		 */
 		$content_from = $compare_from ? apply_filters( "_wp_post_revision_field_{$field}", $compare_from->$field, $field, $compare_from, 'from' ) : '';
 
@@ -155,10 +157,9 @@
  *
  * @since 3.6.0
  *
- * @param object|int $post                 The post object. Also accepts a post ID.
- * @param int        $selected_revision_id The selected revision ID.
- * @param int        $from                 Optional. The revision ID to compare from.
- *
+ * @param WP_Post|int $post                 The post object or post ID.
+ * @param int         $selected_revision_id The selected revision ID.
+ * @param int         $from                 Optional. The revision ID to compare from.
  * @return array An associative array of revision data and related settings.
  */
 function wp_prepare_revisions_for_js( $post, $selected_revision_id, $from = null ) {
@@ -238,6 +239,7 @@
 			'author'     => $authors[ $revision->post_author ],
 			'date'       => date_i18n( __( 'M j, Y @ H:i' ), $modified ),
 			'dateShort'  => date_i18n( _x( 'j M @ H:i', 'revision date short format' ), $modified ),
+			/* translators: %s: Human-readable time difference. */
 			'timeAgo'    => sprintf( __( '%s ago' ), human_time_diff( $modified_gmt, $now_gmt ) ),
 			'autosave'   => $autosave,
 			'current'    => $current,
@@ -280,6 +282,7 @@
 			'author'     => $authors[ $post->post_author ],
 			'date'       => date_i18n( __( 'M j, Y @ H:i' ), strtotime( $post->post_modified ) ),
 			'dateShort'  => date_i18n( _x( 'j M @ H:i', 'revision date short format' ), strtotime( $post->post_modified ) ),
+			/* translators: %s: Human-readable time difference. */
 			'timeAgo'    => sprintf( __( '%s ago' ), human_time_diff( strtotime( $post->post_modified_gmt ), $now_gmt ) ),
 			'autosave'   => false,
 			'current'    => true,
@@ -309,7 +312,7 @@
 	// Now, grab the initial diff.
 	$compare_two_mode = is_numeric( $from );
 	if ( ! $compare_two_mode ) {
-		$found = array_search( $selected_revision_id, array_keys( $revisions ) );
+		$found = array_search( $selected_revision_id, array_keys( $revisions ), true );
 		if ( $found ) {
 			$from = array_keys( array_slice( $revisions, $found - 1, 1, true ) );
 			$from = reset( $from );
@@ -335,7 +338,7 @@
 		'from'           => $from,
 		'diffData'       => $diffs,
 		'baseUrl'        => parse_url( admin_url( 'revision.php' ), PHP_URL_PATH ),
-		'compareTwoMode' => absint( $compare_two_mode ), // Apparently booleans are not allowed
+		'compareTwoMode' => absint( $compare_two_mode ), // Apparently booleans are not allowed.
 		'revisionIds'    => array_keys( $revisions ),
 	);
 }
@@ -345,7 +348,7 @@
  *
  * @since 4.1.0
  *
- * @global WP_Post $post The global `$post` object.
+ * @global WP_Post $post Global post object.
  */
 function wp_print_revision_templates() {
 	global $post;
@@ -394,6 +397,7 @@
 						<span class="byline">
 						<?php
 						printf(
+							/* translators: %s: User's display name. */
 							__( 'Autosave by %s' ),
 							'<span class="author-name">{{ data.attributes.author.name }}</span>'
 						);
@@ -403,6 +407,7 @@
 						<span class="byline">
 						<?php
 						printf(
+							/* translators: %s: User's display name. */
 							__( 'Current Revision by %s' ),
 							'<span class="author-name">{{ data.attributes.author.name }}</span>'
 						);
@@ -412,6 +417,7 @@
 						<span class="byline">
 						<?php
 						printf(
+							/* translators: %s: User's display name. */
 							__( 'Revision by %s' ),
 							'<span class="author-name">{{ data.attributes.author.name }}</span>'
 						);