Allow grow_mode && !bufstart (original assertion logic)

main/streams/streams.c

@@ -1112,7 +1112,8 @@ PHPAPI void *_php_stream_get_line(php_stream *stream, int buf_type, zstr buf, si
 	}
 
 	if (total_copied == 0) {
-		assert(bufstart.v != NULL || !grow_mode || stream->eof);
+		assert(stream->eof || !grow_mode ||
+				(grow_mode && bufstart.v == NULL));
 		return NULL;
 	}
 
@@ -1122,10 +1123,6 @@ PHPAPI void *_php_stream_get_line(php_stream *stream, int buf_type, zstr buf, si
 		buf.s[0] = 0;
 	}
 
-	if (returned_len) {
-		*returned_len = total_copied;
-	}
-
 	return bufstart.s;
 }