I don't want to have key 'u' bound to undo-tree-undo, as it's too conveniently dangerous to confuse with u for universal argument prefix.
But it didn't have any effect. How can I achieve my goal?
Furthermore, the above code has a disasterous effect of redenring key 'u' not working at all. I could not even input letter 'u'.
Edit: based on Drew's suggestion, here is the likely relevant key map:
undo-tree-map is a variable defined in ‘undo-tree.el’. Its value is shown below. This variable may be risky if used as a file-local variable. Documentation: Keymap used in undo-tree-mode. Value: (keymap (24 keymap (114 keymap (85 . undo-tree-restore-state-from-register) (117 . undo-tree-save-state-to-register)) (117 . undo-tree-visualize)) (27 keymap (95 . undo-tree-redo)) (67108927 . undo-tree-redo) (31 . undo-tree-undo) (67108911 . undo-tree-undo) (remap keymap (redo . undo-tree-redo) (undo-only . undo-tree-undo) (undo . undo-tree-undo)))
I still need help (an example) on how to manipulate it. Especially, how to translate the numbers to the key name to understand further how to modify.