MAGETWO-66765: Let less continue compilation if file is empty #7294

Author: vrann

lib/internal/Magento/Framework/Css/PreProcessor/Adapter/Less/Processor.php

@@ -88,13 +88,11 @@ public function processContent(File $asset)
             gc_enable();
 
             if (trim($content) === '') {
-                $errorMessage = PHP_EOL . self::ERROR_MESSAGE_PREFIX . PHP_EOL . $path;
-                $this->logger->critical($errorMessage);
-
-                throw new ContentProcessorException(new Phrase($errorMessage));
+                $this->logger->warning('Parsed less file is empty: ' .  $path);
+                return '';
+            } else {
+                return $content;
             }
-
-            return $content;
         } catch (\Exception $e) {
             throw new ContentProcessorException(new Phrase($e->getMessage()));
         }