Open a Swagger or OAS3 model file in SwagEdit. Make any change, and the "dirty" indicator (an asterisk) appears in the editor tab title. Undo the change (^Z in Windows, by default), and the change is undone but the dirty flag remains. Attempting to close the editor causes dialog offering to save the editor.
Editing the same file with YEdit or the basic "Text Editor" manages dirty status correctly.
Reported by @andylowry:
Seen in current master build of API Studio:
Open a Swagger or OAS3 model file in SwagEdit. Make any change, and the "dirty" indicator (an asterisk) appears in the editor tab title. Undo the change (^Z in Windows, by default), and the change is undone but the dirty flag remains. Attempting to close the editor causes dialog offering to save the editor.
Editing the same file with YEdit or the basic "Text Editor" manages dirty status correctly.