Update fish_vi_key_bindings.fish

[xiruizhao]

Description

add bindings for undo and redo

TODOs:

• Changes to fish usage are reflected in user documentation/manpages.
• Tests have been added for regressions fixed
• User-visible changes noted in CHANGELOG.rst

[faho]

These are already bound to history-search-backward/forward:

fish-shell/share/functions/fish_vi_key_bindings.fish

Lines 104 to 105 in 783736c

	bind -s --preset u history-search-backward
	bind -s --preset \cr history-search-forward

Given that undo is also not bound in readline's vi-mode I prefer not to change the default here. Sorry!

[xiruizhao]

In readline 8.1, u is bound to vi-undo, although C-R is bound to reverse-search-history. Conforming to vim bindings is a better idea.

[krobelus]

In readline 8.1, u is bound to vi-undo

I think it makes sense to do the same; the history search one is not a big loss given that k already does up-or-search.

It doesn't feel nice: after typing echo , pressing u once doesn't move the cursor.

I also tried binding undo to \c_ in insert mode (like readline) but hit #7910.

[faho]

In that case, we should however remove the previous bindings.

[xiruizhao]

What about binding previous ones to / and ? ? Removing them is also fine.

[faho]

A vi-bindings user would have to decide that. I don't know what makes sense here.

(Also note that my bash with readline 8.1 does not have "u" bound to vi-undo - INPUTRC=/dev/null bash -c 'bind -Pm vi' says nothing about vi-undo or "u")

[xiruizhao]

I just tried, u actually binds to vi-undo in bash 5.1.4 (this is also reflected in source code https://github.com/bminor/bash/blob/f3a35a2d601a55f337f8ca02a541f8c033682247/lib/readline/vi_keymap.c#L165), probably a bug of bind?

[faho]

Doesn't happen for me. u doesn't appear to be doing anything. Probably some compile-time settings again (I've checked my local customization, I have very little of it and nothing that should apply to vi-mode let alone u).

[faho]

Ah, no undo is just weirder than I thought - it doesn't undo entering text, but if I dw then it'll undo something. Still not displayed in bind -P.

[xiruizhao]

The bind bug is probably due to https://github.com/bminor/bash/blob/f3a35a2d601a55f337f8ca02a541f8c033682247/lib/readline/funmap.c#L59 not having vi-undo. I will notify readline's maintainer.

[xiruizhao]

Since j and k include forward/backward history search functionality, I deleted previous bindings. You can reopen this PR and review it. @faho

[krobelus]

@xiruizhao GitHub doesn't allow to reopen after a force push, but I'll cherry-pick your commit and add a changelog entry.

[xiruizhao]

Ah, no undo is just weirder than I thought - it doesn't undo entering text, but if I dw then it'll undo something. Still not displayed in bind -P.

It would be actually nice to undo insertions/paste.

[zanchey]

@xiruizhao GitHub doesn't allow to reopen after a force push, but I'll cherry-pick your commit and add a changelog entry.

That's f66f999 from https://github.com/xiruizhao/fish-shell/tree/patch-1 I take it?

[krobelus]

Sorry for the delay, cherry-picked as 8bbb06b