Redmine

The cause is that the start position (subject_left) did not include the width of the folding icon.
Solved by the following patch (Firefox, Chrome, Safari, IE11, Edge confirmed).

diff --git a/public/javascripts/gantt.js b/public/javascripts/gantt.js
index ebaaa2b46..efda080ee 100644
--- a/public/javascripts/gantt.js
+++ b/public/javascripts/gantt.js
@@ -231,8 +231,9 @@ function resizableSubjectColumn(){
 }

 ganttEntryClick = function(e){
-  var subject = $(e.target.parentElement);
-  var subject_left = parseInt(subject.css('left'));
+  var icon_expander = e.target;
+  var subject = $(icon_expander.parentElement);
+  var subject_left = parseInt(subject.css('left')) + parseInt(icon_expander.offsetWidth);
   var target_shown = null;
   var target_top = 0;
   var total_height = 0;