fluff: Avoid using Morebits.queryString to parse the url for 'oldid'

The url on diffs and old revisions is fickle, and may not necessarily display exactly what you think or expect based solely on the value of oldid.

- wgRevisionId added in MW 1.22 circa (2013)
- wgDiffOldId and wgDiffNewId added in MW 1.30 (2017)

modules/twinklefluff.js

@@ -33,7 +33,7 @@ var buildLink = function(color, text) {
 
 Twinkle.fluff = {
 	auto: function() {
-		if( parseInt( Morebits.queryString.get('oldid'), 10) !== mw.config.get('wgCurRevisionId') ) {
+		if( mw.config.get('wgRevisionId') !== mw.config.get('wgCurRevisionId') ) {
 			// not latest revision
 			alert("Can't rollback, page has changed in the meantime.");
 			return;
@@ -99,13 +99,7 @@ Twinkle.fluff = {
 			return;
 		}
 
-		var old_rev_url = $("#mw-diff-otitle1").find("strong a").attr("href");
-
 		// Lets first add a [restore this revision] link
-		var query = new Morebits.queryString( old_rev_url.split( '?', 2 )[1] );
-
-		var oldrev = query.get('oldid');
-
 		var revertToRevision = document.createElement('div');
 		revertToRevision.setAttribute( 'id', 'tw-revert-to-orevision' );
 		revertToRevision.style.fontWeight = 'bold';
@@ -114,24 +108,21 @@ Twinkle.fluff = {
 
 		revertToRevisionLink.href = "#";
 		$(revertToRevisionLink).click(function(){
-			Twinkle.fluff.revertToRevision(oldrev);
+			Twinkle.fluff.revertToRevision(mw.config.get('wgDiffOldId').toString());
 		});
 
 		revertToRevision.appendChild(revertToRevisionLink);
 		otitle.insertBefore( revertToRevision, otitle.firstChild );
 
 		if( document.getElementById('differences-nextlink') ) {
 			// Not latest revision
-			var new_rev_url = $("#mw-diff-ntitle1").find("strong a").attr("href");
-			query = new Morebits.queryString( new_rev_url.split( '?', 2 )[1] );
-			var newrev = query.get('oldid');
 			revertToRevision = document.createElement('div');
 			revertToRevision.setAttribute( 'id', 'tw-revert-to-nrevision' );
 			revertToRevision.style.fontWeight = 'bold';
 			revertToRevisionLink = buildLink('SaddleBrown', 'restore this version');
 			revertToRevisionLink.href = "#";
 			$(revertToRevisionLink).click(function(){
-				Twinkle.fluff.revertToRevision(newrev);
+				Twinkle.fluff.revertToRevision(mw.config.get('wgDiffNewId').toString());
 			});
 			revertToRevision.appendChild(revertToRevisionLink);
 			ntitle.insertBefore( revertToRevision, ntitle.firstChild );