Merge pull request #651 from magento-okapis/MAGETWO-58895-compare_products_2.1.x

Fixed issues:
 - MAGETWO-58895: [Backport] Customer is redirected to "Compare Products" Frontend page if tries to remove a Product from comparing - 2.1

Author: Oleksii Korshenko

app/code/Magento/Catalog/Helper/Product/Compare.php

@@ -228,10 +228,9 @@ public function getRemoveUrl()
      */
     public function getPostDataRemove($product)
     {
-        $listCleanUrl = $this->getEncodedUrl($this->_getUrl('catalog/product_compare'));
         $data = [
-            \Magento\Framework\App\ActionInterface::PARAM_NAME_URL_ENCODED => $listCleanUrl,
-            'product' => $product->getId()
+            \Magento\Framework\App\ActionInterface::PARAM_NAME_URL_ENCODED => '',
+            'product' => $product->getId(),
         ];
         return $this->postHelper->getPostData($this->getRemoveUrl(), $data);
     }
@@ -253,9 +252,8 @@ public function getClearListUrl()
      */
     public function getPostDataClearList()
     {
-        $refererUrl = $this->_getRequest()->getServer('HTTP_REFERER');
         $params = [
-            \Magento\Framework\App\ActionInterface::PARAM_NAME_URL_ENCODED => $this->urlEncoder->encode($refererUrl)
+            \Magento\Framework\App\ActionInterface::PARAM_NAME_URL_ENCODED => '',
         ];
         return $this->postHelper->getPostData($this->getClearListUrl(), $params);
     }

app/code/Magento/Catalog/Test/Unit/Helper/Product/CompareTest.php

@@ -107,18 +107,13 @@ public function testGetPostDataRemove()
         //Data
         $productId = 1;
         $removeUrl = 'catalog/product_compare/remove';
-        $compareListUrl = 'catalog/product_compare';
         $postParams = [
-            Action::PARAM_NAME_URL_ENCODED => strtr(base64_encode($compareListUrl), '+/=', '-_,'),
+            Action::PARAM_NAME_URL_ENCODED => '',
             'product' => $productId
         ];
 
         //Verification
-        $this->urlBuilder->expects($this->at(0))
-            ->method('getUrl')
-            ->with($compareListUrl)
-            ->will($this->returnValue($compareListUrl));
-        $this->urlBuilder->expects($this->at(1))
+        $this->urlBuilder->expects($this->once())
             ->method('getUrl')
             ->with($removeUrl)
             ->will($this->returnValue($removeUrl));
@@ -153,18 +148,12 @@ public function testGetClearListUrl()
     public function testGetPostDataClearList()
     {
         //Data
-        $refererUrl = 'home/';
         $clearUrl = 'catalog/product_compare/clear';
         $postParams = [
-            Action::PARAM_NAME_URL_ENCODED => strtr(base64_encode($refererUrl), '+/=', '-_,')
+            Action::PARAM_NAME_URL_ENCODED => ''
         ];
 
         //Verification
-        $this->request->expects($this->once())
-            ->method('getServer')
-            ->with('HTTP_REFERER')
-            ->will($this->returnValue($refererUrl));
-
         $this->urlBuilder->expects($this->once())
             ->method('getUrl')
             ->with($clearUrl)