closeder/readdir/rewinddir must work only with directories

ext/standard/dir.c

@@ -260,6 +260,11 @@ PHP_FUNCTION(closedir)
 
 	FETCH_DIRP();
 
+	if (!(dirp->flags & PHP_STREAM_FLAG_IS_DIR)) {
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "%d is not a valid Directory resource", dirp->rsrc_id);
+		RETURN_FALSE;
+	}
+
 	rsrc_id = dirp->rsrc_id;
 	zend_list_delete(dirp->rsrc_id);
 
@@ -360,6 +365,11 @@ PHP_FUNCTION(rewinddir)
 	
 	FETCH_DIRP();
 
+	if (!(dirp->flags & PHP_STREAM_FLAG_IS_DIR)) {
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "%d is not a valid Directory resource", dirp->rsrc_id);
+		RETURN_FALSE;
+	}
+
 	php_stream_rewinddir(dirp);
 }
 /* }}} */
@@ -374,6 +384,11 @@ PHP_NAMED_FUNCTION(php_if_readdir)
 
 	FETCH_DIRP();
 
+	if (!(dirp->flags & PHP_STREAM_FLAG_IS_DIR)) {
+		php_error_docref(NULL TSRMLS_CC, E_WARNING, "%d is not a valid Directory resource", dirp->rsrc_id);
+		RETURN_FALSE;
+	}
+
 	if (php_stream_readdir(dirp, &entry)) {
 		RETURN_STRINGL(entry.d_name, strlen(entry.d_name), 1);
 	}

main/php_streams.h

@@ -181,6 +181,8 @@ struct _php_stream_wrapper	{
 
 #define PHP_STREAM_FLAG_NO_CLOSE					32
 	
+#define PHP_STREAM_FLAG_IS_DIR						64
+
 struct _php_stream  {
 	php_stream_ops *ops;
 	void *abstract;  		/* convenience pointer for abstraction */

main/streams/streams.c

@@ -1706,7 +1706,7 @@ PHPAPI php_stream *_php_stream_opendir(char *path, int options,
 
 		if (stream) {
 			stream->wrapper = wrapper;
-			stream->flags |= PHP_STREAM_FLAG_NO_BUFFER;
+			stream->flags |= PHP_STREAM_FLAG_NO_BUFFER | PHP_STREAM_FLAG_IS_DIR;
 		}
 	} else if (wrapper) {
 		php_stream_wrapper_log_error(wrapper, options ^ REPORT_ERRORS TSRMLS_CC, "not implemented");