main/streams: Remove questionable use of PHP_STRLCPY

The description of PHP_STRLCPY says that this is a fast version of strlcpy that should be used if we *know* the size of both the source and destination buffers.
This is clearly not the case as we use strlen() to compute it.
Moreover if the result cannot fit in the destination buffer something seriously strange has happened and we should return a failure state rather than truncating.

Author: Girgias

main/streams/plain_wrapper.c

@@ -1028,7 +1028,12 @@ static ssize_t php_plain_files_dirstream_read(php_stream *stream, char *buf, siz
 
 	result = readdir(dir);
 	if (result) {
-		PHP_STRLCPY(ent->d_name, result->d_name, sizeof(ent->d_name), strlen(result->d_name));
+		size_t len = strlen(result->d_name);
+		if (UNEXPECTED(len >= sizeof(ent->d_name))) {
+			return -1;
+		}
+		/* Include null byte */
+		memcpy(ent->d_name, result->d_name, len+1);
 #ifdef _DIRENT_HAVE_D_TYPE
 		ent->d_type = result->d_type;
 #else