Fix section checkboxes when frozen

Author: patosai

src/tree-multiselect/tree.js

@@ -245,9 +245,7 @@ Tree.prototype.redrawSectionCheckboxes = function ($section) {
   if (returnVal) {
     let $childCheckboxes = $section.find('> div.item > input[type=checkbox]');
     for (let ii = 0; ii < $childCheckboxes.length; ++ii) {
-      if ($childCheckboxes[ii].disabled) {
-        // do nothing
-      } else if ($childCheckboxes[ii].checked) {
+      if ($childCheckboxes[ii].checked) {
         returnVal &= ~0b10;
       } else {
         returnVal &= ~0b01;

test/integration/options.test.js

@@ -146,6 +146,21 @@ describe('Options', () => {
     assert.equal(removeSpans.length, 0);
   });
 
+  it('section checkboxes are indetermine if some children are selected', () => {
+    $("select").append("<option value='one' data-section='test'>One</option>");
+    $("select").append("<option value='two' data-section='test' selected='selected'>Two</option>");
+    var options = {
+      freeze: true
+    };
+    $("select").treeMultiselect(options);
+
+    var $sectionCheckbox = Common.sectionCheckbox({text: 'test'});
+    assert.equal($sectionCheckbox.length, 1);
+    var checkbox = $sectionCheckbox[0];
+    assert(checkbox.indeterminate);
+    assert(!checkbox.checked);
+  });
+
   it('applies only to one tree and not another', () => {
     $("select").append("<option value='one' data-section='test'>One</option>");
     $("select").treeMultiselect();