MAGETWO-45563: Cannot manually add products to a configurable product

Author: Michail Slabko

app/code/Magento/ConfigurableProduct/view/adminhtml/web/js/variations/product-grid.js

@@ -135,7 +135,7 @@ define([
          */
         close: function (rowIndex) {
             try {
-                if (this.productsMassAction().selected.length) {
+                if (this.productsMassAction().selected.getLength()) {
                     this.variationsComponent()[this.callbackName](this.productsMassAction()
                         .selected.map(this.getProductById.bind(this)));
                     this.productsMassAction().deselectAll();

app/code/Magento/ConfigurableProduct/view/adminhtml/web/js/variations/variations.js

@@ -48,17 +48,24 @@ define([
         },
         showGrid: function (rowIndex) {
             var product = this.productMatrix()[rowIndex],
-                attributes = JSON.parse(product.attribute);
+                attributes = JSON.parse(product.attribute),
+                filterModifier = product.productId ? {
+                    'entity_id': {
+                        'condition_type': 'neq', value: product.productId
+                    }
+                 } : {};
             this.rowIndexToEdit = rowIndex;
 
+            filterModifier = _.extend(filterModifier, _.mapObject(attributes, function (value) {
+                return {
+                    'condition_type': 'eq',
+                    'value': value
+                };
+            }));
             this.associatedProductGrid().open(
                 {
                     'filters': attributes,
-                    'filters_modifier': product.productId ? {
-                        'entity_id': {
-                            'condition_type': 'neq', value: product.productId
-                        }
-                    } : {}
+                    'filters_modifier': filterModifier
                 },
                 'changeProduct',
                 false