Index: wp-admin/includes/ajax-actions.php
===================================================================
--- wp-admin/includes/ajax-actions.php	(revision 23900)
+++ wp-admin/includes/ajax-actions.php	(working copy)
@@ -2186,6 +2186,7 @@
 			continue;
 
 		$revision_from_date_author = '';
+		$is_current_revision = false;
 		$count++;
 		// return blank data for diffs to the left of the left handle (for right handel model)
 		// or to the right of the right handle (for left handel model)
@@ -2235,10 +2236,12 @@
 		elseif ( wp_is_post_autosave( $left_revision ) )
 			$revision_from_date_author = sprintf( $autosavef, $revision_from_date_author );
 
-		if ( $revision->post_modified === $post->post_modified )
+		if ( $revision->post_modified === $post->post_modified ) {
 			$revision_date_author = sprintf( $currentf, $revision_date_author );
-		elseif ( wp_is_post_autosave( $revision ) )
+			$is_current_revision = true;
+		} elseif ( wp_is_post_autosave( $revision ) ) {
 			$revision_date_author = sprintf( $autosavef, $revision_date_author );
+		}
 
 		/* translators: revision date short format, see http://php.net/date */
 		$date_short_format = _x( 'j M @ G:i', 'revision date short format');
@@ -2275,7 +2278,8 @@
 				'titleTooltip'         => $revision_date_author_short,
 				'restoreLink'          => urldecode( $restore_link ),
 				'revision_toload'      => true,
-				'previous_revision_id' => $previous_revision_id
+				'previous_revision_id' => $previous_revision_id,
+				'is_current_revision'  => $is_current_revision,
 			);
 		}
 		$previous_revision_id = $revision->ID;
Index: wp-admin/js/revisions.js
===================================================================
--- wp-admin/js/revisions.js	(revision 23900)
+++ wp-admin/js/revisions.js	(working copy)
@@ -639,11 +639,7 @@
 			this.toogleCompareTwoCheckbox();
 
 			// hide the restore button when on the last sport/current post data
-			if ( Diff.rightDiff === Diff.revisions.length ){
-				$( '#restore' ).hide();
-			} else {
-				$( '#restore' ).show();
-			}
+			$( '#restore' ).toggle( ! Diff.revisions.at( Diff.rightDiff - 1 ).get( 'is_current_revision' ) );
 
 			return this;
 		},
@@ -709,7 +705,8 @@
 			lines_added: 0,
 			lines_deleted: 0,
 			scope_of_changes: 'none',
-			previous_revision_id: 0
+			previous_revision_id: 0,
+			is_current_revision: false
 		},
 
 		url: function() {