Using zvm_bindkey to bind widget to "ESC-<key>" renders backslash unusable

[cohml]

General information

• Terminal program: iTerm.app 3.4.23 (xterm-256color)
• Operating system: macOS 14.2.1 (23C71)
• ZSH framework: oh-my-zsh master (f7b647e1)
• ZSH version: zsh 5.9 (x86_64-apple-darwin23.0)
• ZVM version: zsh-vi-mode 0.11.0

Basic examination

• I have read through the README page
• I have the latest version of zsh-vi-mode
• I have tested with another terminal program

Problem description

The README states that custom widgets should be bound to a key (or key sequence) using zvm_bindkeys. However, in certain cases, zvm_bindkey can "steal" the first key of the sequence and bind it to zvm_readkeys_handler.

When the sequence begins with ESC - for which I believe the ANSI escape code is \e - this means that \ gets bound to zvm_readkeys_handler, making it impossible to type out a backslash.

After reading the source code, I'm quite certain the offending logic occurs here:

https://github.com/jeffreytse/zsh-vi-mode/blob/master/zsh-vi-mode.zsh#L608-L622C33

Reproduction steps

❯ # define arbitrary function
❯ function foo() {}
❯ 
❯ # register function as zsh widget
❯ zle -N foo
❯ 
❯ # note that zvm_readkeys_handler IS NOT bound to backslash
❯ bindkey -L | grep zvm_readkeys_handler
bindkey "^[" zvm_readkeys_handler
❯ 
❯ # note that i can still type backslashes
❯ \\\
❯ 
❯ # use zvm_bindkey to bind function to sequence beginning with backslash
❯ zvm_bindkey viins "\ef" foo
❯ 
❯ # note that zvm_readkeys_handler IS now bound to backslash
❯ bindkey -L | grep zvm_readkeys_handler
bindkey "^[" zvm_readkeys_handler
bindkey "\\\\" zvm_readkeys_handler
❯ 
❯ # i am unable to type backslashes
❯
❯ # when i try, it seems to try to register the subsequent key as a widget;
❯ # for example, here i will press "\f"
❯
No such widget `f'

Expected behavior

My widget should be bound to the specified sequence without rendering the initial key in the sequence unusable on its own.