From abb5646eb1785c7040c039131c92f6684c71e933 Mon Sep 17 00:00:00 2001
From: Rob Garrison <wowmotty@gmail.com>
Date: Sat, 3 Oct 2015 22:11:02 -0500
Subject: [PATCH] Core: Remove tabindex when sort is disabled

See http://stackoverflow.com/a/16827628/145346
---
 js/jquery.tablesorter.js | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/js/jquery.tablesorter.js b/js/jquery.tablesorter.js
index b941b5bd..81369e61 100644
--- a/js/jquery.tablesorter.js
+++ b/js/jquery.tablesorter.js
@@ -513,19 +513,27 @@
 			}
 
 			function updateHeader(table) {
-				var index, s, $th, col,
+				var index, isDisabled, $th, col,
 					c = table.config,
 					len = c.$headers.length;
 				for ( index = 0; index < len; index++ ) {
 					$th = c.$headers.eq( index );
 					col = ts.getColumnData( table, c.headers, index, true );
 					// add 'sorter-false' class if 'parser-false' is set
-					s = ts.getData( $th, col, 'sorter' ) === 'false' || ts.getData( $th, col, 'parser' ) === 'false';
-					$th[0].sortDisabled = s;
-					$th[ s ? 'addClass' : 'removeClass' ]('sorter-false').attr('aria-disabled', '' + s);
+					isDisabled = ts.getData( $th, col, 'sorter' ) === 'false' || ts.getData( $th, col, 'parser' ) === 'false';
+					$th[0].sortDisabled = isDisabled;
+					$th[ isDisabled ? 'addClass' : 'removeClass' ]( 'sorter-false' ).attr( 'aria-disabled', '' + isDisabled );
+					// disable tab index on disabled cells
+					if ( c.tabIndex ) {
+						if ( isDisabled ) {
+							$th.removeAttr( 'tabindex' );
+						} else {
+							$th.attr( 'tabindex', '0' );
+						}
+					}
 					// aria-controls - requires table ID
 					if (table.id) {
-						if (s) {
+						if ( isDisabled ) {
 							$th.removeAttr('aria-controls');
 						} else {
 							$th.attr('aria-controls', table.id);