v0.6.3 Fix for tests

Author: flying-sheep

DESCRIPTION

@@ -3,7 +3,7 @@ Title: 'Jupyter' Display Machinery
 Description:
     An interface to the rich display capabilities of 'Jupyter' front-ends (e.g. 'Jupyter Notebook') <https://jupyter.org>.
     Designed to be used from a running 'IRkernel' session <https://irkernel.github.io>.
-Version: 0.6.2.9000
+Version: 0.6.3
 Authors@R: c(
     person('Thomas', 'Kluyver', role = c('aut', 'cph'), email = 'thomas@kluyver.me.uk'),
     person('Philipp', 'Angerer', role = c('aut', 'cph', 'cre'), email = 'phil.angerer@gmail.com', comment = c(ORCID = "0000-0002-0369-2888")),

R/display.r

@@ -47,7 +47,9 @@ display <- function(
     mimetypes = getOption('jupyter.display_mimetypes'),
     error_handler = stop
 ) {
-    bundle <- prepare_mimebundle(obj, mimetypes, list(...), error_handler)
+    metadata <- list(...)
+    if (length(metadata) == 0L) metadata <- NULL
+    bundle <- prepare_mimebundle(obj, mimetypes, metadata, error_handler)
     publish_mimebundle(bundle$data, bundle$metadata)
 }