Merge pull request #5928 from mishaschwartz/persist-cell-id

Ensure that cell ids persist after save

notebook/static/notebook/js/cell.js

@@ -490,6 +490,9 @@ define([
         var data = {};
         // deepcopy the metadata so copied cells don't share the same object
         data.metadata = JSON.parse(JSON.stringify(this.metadata));
+        if (this.id !== undefined) {
+            data.id = this.id;
+        }
         if (data.metadata.deletable) {
             delete data.metadata.deletable;
         }
@@ -511,6 +514,9 @@ define([
         if (data.metadata !== undefined) {
             this.metadata = data.metadata;
         }
+        if (data.id !== undefined) {
+            this.id = data.id;
+        }
     };
 
 

notebook/static/notebook/js/notebook.js

@@ -1648,6 +1648,9 @@ define([
             if (cell_json.metadata.deletable !== undefined) {
                 delete cell_json.metadata.deletable;
             }
+            if (cell_json.id !== undefined) {
+                delete cell_json.id;
+            }
             this.clipboard.push(cell_json);
         }
         this.enable_paste();