Fix #13846: .prev sort direction

src/traversing.js

 var isSimple = /^.[^:#\[\.,]*$/,
+	rparentsprev = /^(?:parents|prev(?:Until|All))/,
 	rneedsContext = jQuery.expr.match.needsContext,
 	// methods guaranteed to produce a unique set when starting from a unique set
 	guaranteedUnique = {
@@ -200,8 +201,8 @@ jQuery.each({
 				jQuery.unique( matched );
 			}
 
-			// Reverse order for parents* and prev*
-			if ( name[ 0 ] === "p" && name !== "parent" ) {
+			// Reverse order for parents* and prev-derivatives
+			if ( rparentsprev.test( name ) ) {
 				matched.reverse();
 			}
 		}

test/unit/traversing.js

@@ -682,7 +682,7 @@ test("sort direction", function() {
 			parents: true,
 			parentsUntil: true,
 			next: false,
-			prev: true,
+			prev: false,
 			nextAll: false,
 			prevAll: true,
 			nextUntil: false,