Don't return categoryId from registry if the product doesn't belong in current category

Author: ErikPel

app/code/Magento/Catalog/Model/Product.php

@@ -727,7 +727,7 @@ public function getIdBySku($sku)
     public function getCategoryId()
     {
         $category = $this->_registry->registry('current_category');
-        if ($category) {
+        if ($category && in_array($category->getId(), $this->getCategoryIds())) {
             return $category->getId();
         }
         return false;

app/code/Magento/Catalog/Test/Unit/Model/ProductTest.php

@@ -549,6 +549,7 @@ public function testSetCategoryCollection()
 
     public function testGetCategory()
     {
+        $this->model->setData('category_ids', [10]);
         $this->category->expects($this->any())->method('getId')->will($this->returnValue(10));
         $this->registry->expects($this->any())->method('registry')->will($this->returnValue($this->category));
         $this->categoryRepository->expects($this->any())->method('get')->will($this->returnValue($this->category));
@@ -557,14 +558,23 @@ public function testGetCategory()
 
     public function testGetCategoryId()
     {
-        $this->category->expects($this->once())->method('getId')->will($this->returnValue(10));
+        $this->model->setData('category_ids', [10]);
+        $this->category->expects($this->any())->method('getId')->will($this->returnValue(10));
 
         $this->registry->expects($this->at(0))->method('registry');
         $this->registry->expects($this->at(1))->method('registry')->will($this->returnValue($this->category));
         $this->assertFalse($this->model->getCategoryId());
         $this->assertEquals(10, $this->model->getCategoryId());
     }
 
+    public function testGetCategoryIdWhenProductNotInCurrentCategory()
+    {
+        $this->model->setData('category_ids', [12]);
+        $this->category->expects($this->once())->method('getId')->will($this->returnValue(10));
+        $this->registry->expects($this->any())->method('registry')->will($this->returnValue($this->category));
+        $this->assertFalse($this->model->getCategoryId());
+    }
+
     public function testGetIdBySku()
     {
         $this->resource->expects($this->once())->method('getIdBySku')->will($this->returnValue(5));

dev/tests/integration/testsuite/Magento/Catalog/Model/ProductExternalTest.php

@@ -69,7 +69,7 @@ public function testGetCategoryId()
     {
         $this->assertFalse($this->_model->getCategoryId());
         $category = new \Magento\Framework\DataObject(['id' => 5]);
-
+        $this->_model->setCategoryIds([5]);
         $this->objectManager->get(\Magento\Framework\Registry::class)->register('current_category', $category);
         try {
             $this->assertEquals(5, $this->_model->getCategoryId());
@@ -83,6 +83,7 @@ public function testGetCategoryId()
     public function testGetCategory()
     {
         $this->assertEmpty($this->_model->getCategory());
+        $this->_model->setCategoryIds([3]);
 
         $this->objectManager->get(\Magento\Framework\Registry::class)
             ->register('current_category', new \Magento\Framework\DataObject(['id' => 3]));