[gnome-builder/wip/gtk4-port] plugins/editorui: fix fallback detection

[Christian Hergert <chergert src gnome org>]

commit 9eb78c578f34194c6dd5338487b4e8320a482d7d
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jun 7 20:58:02 2022 -0700

    plugins/editorui: fix fallback detection

 src/plugins/editorui/gbp-editorui-workbench-addin.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/plugins/editorui/gbp-editorui-workbench-addin.c 
b/src/plugins/editorui/gbp-editorui-workbench-addin.c
index 4265a57b3..576343f2e 100644
--- a/src/plugins/editorui/gbp-editorui-workbench-addin.c
+++ b/src/plugins/editorui/gbp-editorui-workbench-addin.c
@@ -120,7 +120,7 @@ gbp_editorui_workbench_addin_can_open (IdeWorkbenchAddin *addin,
     {
       static char *text_plain_type;
 
-      if G_UNLIKELY (text_plain_type)
+      if G_UNLIKELY (text_plain_type == NULL)
         text_plain_type = g_content_type_from_mime_type ("text/plain");
 
       if (g_content_type_is_a (content_type, text_plain_type))