In Gedit, I installed the line_tools plugin. It uses Ctrl+D to duplicate the the current line. When I pressed Ctrl+D, it did the opposite! It deleted the line instead!
It turns out that Gedit has an unlisted (not in the menu) shortcut-key: Ctrl+D, which deletes a line.
It is quite simple to change any menu item's shortcut-key in Gedit by enabling Editable Menu Accelerators, but I can't change this delete-line action's key, because there is no menu item for it!
How can I override this delete-line action? .. and what other unlisted actions does Gedit have? .. and why is it (they?) unlisted?
PS: The developer of the 'line_tools' provides the plugin with Ctrl+D set to 'Duplicate'.. I assume he tested it; which would suggest that there was no such clash circa 2008-01-30 (the timestamp on the downloaded