[zsh] `CTRL-R` inserting number and binding with FZF_DEFAULT_OPTIONS set

[aravance]

• [x] I have read through the manual page (man fzf)
• [x] I have the latest version of fzf
• [x] I have searched through the existing issues

Info

• OS
  • [x] Linux
  • [ ] Mac OS X
  • [ ] Windows
  • [ ] Etc.
• Shell
  • [ ] bash
  • [x] zsh
  • [ ] fish

Problem / Steps to reproduce

Case 1

1. export FZF_DEFAULT_OPTS="--expect=ctrl-y"
2. <ctrl-r>
3. select an option with <enter>

expected:

$ echo $FZF_DEFAULT_OPTS

actual:

$ 
 5613  echo $FZF_DEFAULT_OPTS

Case 2

1. export FZF_DEFAULT_OPTS="--expect=ctrl-y"
2. <ctrl-r>
3. select an option with <ctrl-y>

expected:

$ echo $FZF_DEFAULT_OPTS

actual:

$ ctrl-y
 5613  echo $FZF_DEFAULT_OPTS

[aravance]

Likely related: #3591

[junegunn]

You should never put --expect in your FZF_DEFAULT_OPTS. When --expect is given and you press enter or any of the specified keys, fzf will print the name of the key as the first line. This will break every script that doesn't expect an extra line.