Index: branches/5.2.x/core/units/helpers/upload_helper.php
===================================================================
diff -u -N -r16561 -r16596
--- branches/5.2.x/core/units/helpers/upload_helper.php	(.../upload_helper.php)	(revision 16561)
+++ branches/5.2.x/core/units/helpers/upload_helper.php	(.../upload_helper.php)	(revision 16596)
@@ -16,12 +16,21 @@
 {
 
 	/**
+	 * File helper reference
+	 *
+	 * @var FileHelper
+	 */
+	protected $fileHelper = null;
+
+	/**
 	 * Creates kUploadHelper instance.
 	 */
 	public function __construct()
 	{
 		parent::__construct();
 
+		$this->fileHelper = $this->Application->recallObject('FileHelper');
+
 		// 5 minutes execution time
 		@set_time_limit(5 * 60);
 	}
@@ -77,23 +86,13 @@
 			throw new kUploaderException('Write permissions not set on the server, please contact server administrator.', 500);
 		}
 
-		/** @var FileHelper $file_helper */
-		$file_helper = $this->Application->recallObject('FileHelper');
-		$filename = $file_helper->ensureUniqueFilename($tmp_path, $filename);
+		$filename = $this->fileHelper->ensureUniqueFilename($tmp_path, $filename);
 		$storage_format = $this->getStorageFormat($this->Application->GetVar('field'), $event);
+		$this->moveUploadedFile($tmp_path . $filename);
 
 		if ( $storage_format ) {
-			/** @var ImageHelper $image_helper */
-			$image_helper = $this->Application->recallObject('ImageHelper');
-
-			$this->moveUploadedFile($value['tmp_name'] . '.jpg'); // add extension, so ResizeImage can work
-			$url = $image_helper->ResizeImage($value['tmp_name'] . '.jpg', $storage_format);
-			$tmp_name = preg_replace('/^' . preg_quote($this->Application->BaseURL(), '/') . '/', '/', $url);
-			rename($tmp_name, $tmp_path . $filename);
+			$this->resizeUploadedFile($tmp_path . $filename, $storage_format);
 		}
-		else {
-			$this->moveUploadedFile($tmp_path . $filename);
-		}
 
 		$this->deleteTempFiles($tmp_path);
 
@@ -108,6 +107,33 @@
 	}
 
 	/**
+	 * Resizes uploaded file.
+	 *
+	 * @param string $file_path File path.
+	 * @param string $format    Format.
+	 *
+	 * @return boolean
+	 */
+	public function resizeUploadedFile($file_path, $format)
+	{
+		/** @var ImageHelper $image_helper */
+		$image_helper = $this->Application->recallObject('ImageHelper');
+
+		// Add extension, so that "ImageHelper::ResizeImage" can work.
+		$resize_file_path = tempnam(sys_get_temp_dir(), 'uploaded_') . '.jpg';
+
+		if ( rename($file_path, $resize_file_path) === false ) {
+			return false;
+		}
+
+		$resized_file_path = $this->fileHelper->urlToPath(
+			$image_helper->ResizeImage($resize_file_path, $format)
+		);
+
+		return rename($resized_file_path, $file_path);
+	}
+
+	/**
 	 * Sends headers to ensure, that response is never cached.
 	 *
 	 * @return void