Merge pull request #977 from juhasch/fix/codefolding_gutter

Fix codefolding gutter
ipython-contrib · Apr 30, 2017 · dd7d29e · dd7d29e
2 parents 4ce8aa2 + 2d4e3b4
commit dd7d29e
Showing 1 changed file with 5 additions and 5 deletions.
diff --git a/src/jupyter_contrib_nbextensions/nbextensions/codefolding/main.js b/src/jupyter_contrib_nbextensions/nbextensions/codefolding/main.js
@@ -126,11 +126,11 @@ define([
      * @param cell {codecell.CodeCell} code cell to activate folding gutter
      */
     function activate_cm_folding (cm) {
-        var gutters = cm.getOption('gutters');
-        if ($.inArray("CodeMirror-foldgutter", gutters) < 0) {
-            gutters.push('CodeMirror-foldgutter');
-            cm.setOption('gutters', gutters);
-        }
+        var gutters = cm.getOption('gutters').slice();
+        if ( $.inArray("CodeMirror-foldgutter", gutters) < 0) {
+                gutters.push('CodeMirror-foldgutter')
+                cm.setOption('gutters', gutters);
+            }
 
         /* set indent or brace folding */
         var opts = true;