@xiota commented on this pull request.
@@ -167,6 +307,7 @@ PluginCallback plugin_callbacks[] = {
{"document-open", (GCallback) & on_doc_open, TRUE, NULL}, {"document-activate", (GCallback) & on_doc_activate, TRUE, NULL}, {"document-close", (GCallback) & on_doc_close, TRUE, NULL}, + {"document-filetype-set", (GCallback) & on_doc_filetype_set, TRUE, NULL},
I'm looking at the code again, and I guess I did try the document open signal. There must have been some race condition or something that prevented it from working all the time. I don't remember and will retry it by itself to see.