ACP2E-3735: Incorrect filtered Data in Product Export for Multi-Store Setup

- fixed unit test

Author: o-rykh

app/code/Magento/CatalogImportExport/Model/Export/Product.php

@@ -1008,7 +1008,7 @@ public function export()
             $this->paginateCollection($page, $this->getItemsPerPage());
 
             $exportData = $this->getExportData();
-            if (count($exportData) == 0) {
+            if ($exportData == null || count($exportData) == 0) {
                 break;
             }
             if ($page == 1) {

app/code/Magento/CatalogImportExport/Test/Unit/Model/Export/ProductTest.php

@@ -343,8 +343,6 @@ public function testExportCountZeroBreakInternalCalls()
         $this->product->expects($this->once())->method('paginateCollection')->with($page, $itemsPerPage);
         $this->abstractCollection->expects($this->once())->method('setOrder')->with('entity_id', 'asc');
 
-        $this->abstractCollection->expects($this->once())->method('count')->willReturn(0);
-
         $this->abstractCollection->expects($this->never())->method('getCurPage');
         $this->abstractCollection->expects($this->never())->method('getLastPageNumber');
         $this->product->expects($this->never())->method('_getHeaderColumns');