plugin-bookdown.js.patch

--- a/gitbook/js/plugin-bookdown.js
+++ b/gitbook/js/plugin-bookdown.js
@@ -95,12 +95,8 @@
     });
 
     // highlight the current section in TOC
-    var href = window.location.pathname;
-    href = href.substr(href.lastIndexOf('/') + 1);
-    // accentuated characters need to be decoded (#819)
-    href = decodeURIComponent(href);
-    if (href === '') href = 'index.html';
-    var li = $('a[href^="' + href + location.hash + '"]').parent('li.chapter').first();
+    var href = location.hash ? '' : location.hash;
+    var li = $('a[href="' + href + '"]').parent('li.chapter').first();
     var summary = $('ul.summary'), chaps = summary.find('li.chapter');
     if (li.length === 0) li = chaps.first();
     li.addClass('active');
@@ -162,22 +158,22 @@
       }
       if (m === 0) return;
       // all section titles on current page
-      var hs = bookInner.find('.page-inner').find('h1,h2,h3'), n = hs.length,
-          ts = hs.map(function(i, el) { return $(el).text(); });
+      var hs = bookInner.find('.page-inner').find('h1,h2,h3,h4,h5').children('span[class^="ltx_tag"]'), n = hs.length,
+          ts = hs.map(function(i, el) { return ($(el).closest('section').attr('id') ? '#' + $(el).closest('section').attr('id') : ''); });
       if (n === 0) return;
       var scrollHandler = function(e) {
         var ht = $(window).height();
         clearTimeout($.data(this, 'scrollTimer'));
         $.data(this, 'scrollTimer', setTimeout(function() {
-          // find the first visible title in the viewport
+          // find the last section starting by the middle of the viewport
           for (var i = 0; i < n; i++) {
             var rect = hs[i].getBoundingClientRect();
-            if (rect.top >= 0 && rect.bottom <= ht) break;
+            if (rect.top > ht / 2) break;
           }
-          if (i === n) return;
+          if (i > 0) i--;
           items.removeClass('active');
           for (var j = 0; j < m; j++) {
-            if (items.eq(j).children('a').first().text() === ts[i]) break;
+            if (items.eq(j).children('a').attr('href') === ts[i]) break;
           }
           if (j === m) j = 0;  // highlight the chapter title
           // search bottom-up for a visible TOC item to highlight; if an item is
@@ -191,7 +187,7 @@
     })();
 
     // do not refresh the page if the TOC item points to the current page
-    $('a[href="' + href + '"]').parent('li.chapter').children('a')
+    $('a[href=""]').parent('li.chapter').children('a')
       .on('click', function(e) {
         bookInner.scrollTop(0);
         bookBody.scrollTop(0);