Fixed filter issue for w3tc_minify_urls_for_minification_to_minify_filename (#832)

* Fixed filter issue for w3tc_minify_urls_for_minification_to_minify_filena.
* Hash Minify filename for WP Option filter mapping

Author: jacobd91

Minify_Core.php

@@ -24,9 +24,16 @@ static public function urls_for_minification_to_minify_filename( $files, $type )
 		}
 
 		$minify_filename = $key . '.' . $type;
-		$minify_filename = apply_filters(
-			'w3tc_minify_urls_for_minification_to_minify_filename',
-			$minify_filename, $files, $type );
+
+		if ( has_filter( 'w3tc_minify_urls_for_minification_to_minify_filename' ) ) {
+			$minify_filename = apply_filters(
+				'w3tc_minify_urls_for_minification_to_minify_filename',
+				$minify_filename,
+				$files,
+				$type
+			);
+			update_option( 'w3tc_minify_filter_' . hash( 'crc32b', $minify_filename ), $key, false );
+		}
 
 		return $minify_filename;
 	}
@@ -57,7 +64,10 @@ static private function urls_for_minification_to_minify_key( $files_string, $key
 	 * @return array
 	 */
 	static public function minify_filename_to_urls_for_minification( $filename, $type ) {
-		$v = get_option( 'w3tc_minify_' . $filename );
+		$hash = has_filter( 'w3tc_minify_urls_for_minification_to_minify_filename' ) ?
+			get_option( 'w3tc_minify_filter_' . hash( 'crc32b', $filename . '.' . $type ) ) : $filename;
+		$v    = get_option( 'w3tc_minify_' . $hash );
+
 		$urls_unverified = @json_decode( $v, true );
 		if ( !is_array( $urls_unverified ) ) {
 			return array();