From 866e504a82150432ffcb8e2bfb255943fec556f5 Mon Sep 17 00:00:00 2001
From: Matthias Kretschmann <m@kretschmann.io>
Date: Sat, 12 Mar 2016 19:25:24 +0100
Subject: [PATCH] toc.js: fix wrong link being highlighted when page length
 changes dynamically

- from https://github.com/jgallen23/toc/pull/48
---
 assets/_src/js/vendor/toc.js | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/assets/_src/js/vendor/toc.js b/assets/_src/js/vendor/toc.js
index 1beb853..cef6942 100644
--- a/assets/_src/js/vendor/toc.js
+++ b/assets/_src/js/vendor/toc.js
@@ -59,9 +59,17 @@
 
         var container = $(opts.container);
         var headings = $(opts.selectors, container);
-        var headingOffsets = [];
         var activeClassName = opts.activeClass;
 
+        var headingOffsets = function() {
+            var offsets = [];
+            headings.each(function(i, heading) {
+                var $h = $(heading);
+                offsets.push($h.offset().top - opts.highlightOffset);
+            });
+            return offsets;
+        };
+
         var scrollTo = function(e, callback) {
             if (opts.smoothScrolling && typeof opts.smoothScrolling === 'function') {
                 e.preventDefault();
@@ -82,10 +90,11 @@
             timeout = setTimeout(function() {
                 var top = $(window).scrollTop(),
                     highlighted, closest = Number.MAX_VALUE,
-                    index = 0;
+                    index = 0
+                    offsets = headingOffsets();
 
-                for (var i = 0, c = headingOffsets.length; i < c; i++) {
-                    var currentClosest = Math.abs(headingOffsets[i] - top);
+                for (var i = 0, c = offsets.length; i < c; i++) {
+                    var currentClosest = Math.abs(offsets[i] - top);
                     if (currentClosest < closest) {
                         index = i;
                         closest = currentClosest;
@@ -109,7 +118,6 @@
 
             headings.each(function(i, heading) {
                 var $h = $(heading);
-                headingOffsets.push($h.offset().top - opts.highlightOffset);
 
                 var anchorName = opts.anchorName(i, heading, opts.prefix);