Update symbol refs before remove

src/dom_components/model/Component.js

@@ -839,6 +839,15 @@ const Component = Backbone.Model.extend(Styleable).extend(
           symb.append(toAppend, { fromInstance: this, ...o });
         });
       } else {
+        // Remove instance reference from the symbol
+        const symb = m.__getSymbol();
+        symb &&
+          !o.temporary &&
+          symb.set(
+            keySymbols,
+            symb.__getSymbols().filter(i => i !== m)
+          );
+
         // Propagate remove only if the component is an inner symbol
         if (!m.__isSymbolTop()) {
           const { index } = o;
@@ -864,15 +873,6 @@ const Component = Backbone.Model.extend(Styleable).extend(
             });
           toUp.forEach(toUpFn);
         }
-
-        // Remove instance reference from the symbol
-        const symb = m.__getSymbol();
-        symb &&
-          !o.temporary &&
-          symb.set(
-            keySymbols,
-            symb.__getSymbols().filter(i => i !== m)
-          );
       }
 
       this.__changesUp(optUp);
@@ -1428,11 +1428,13 @@ const Component = Backbone.Model.extend(Styleable).extend(
       delete obj.open; // used in Layers
 
       if (!opts.fromUndo) {
-        if (obj[keySymbols]) {
-          obj[keySymbols] = (this.__getSymbols() || []).map(i => i.getId());
+        const symbol = obj[keySymbol];
+        const symbols = obj[keySymbols];
+        if (symbols && isArray(symbols)) {
+          obj[keySymbols] = symbols.map(i => (i.getId ? i.getId() : i));
         }
-        if (obj[keySymbol] && !isString(obj[keySymbol])) {
-          obj[keySymbol] = obj[keySymbol].getId();
+        if (symbol && !isString(symbol)) {
+          obj[keySymbol] = symbol.getId();
         }
       }
 

src/undo_manager/index.js

@@ -48,7 +48,7 @@ export default () => {
      * @private
      */
     init(opts = {}) {
-      config = { ...opts, ...configDef };
+      config = { ...configDef, ...opts };
       em = config.em;
       this.em = em;
       const fromUndo = true;

test/specs/dom_components/model/Symbols.js

@@ -229,6 +229,17 @@ describe('Symbols', () => {
       expect(symbol.__getSymbols().length).toBe(allInst.length - 1);
     });
 
+    test('Removing one instance, works with UndoManager', done => {
+      setTimeout(() => {
+        // This will commit the undo
+        const um = getUm(comp);
+        allInst[0].remove();
+        um.undo();
+        expect(symbol.__getSymbols().length).toBe(allInst.length);
+        done();
+      });
+    });
+
     test('Adding a new component to a symbol, it will be propogated to all instances', () => {
       const added = symbol.append(simpleComp, { at: 0 })[0];
       all.forEach(cmp =>