"zed -h" truncates history

[vapnik spaknik <vapniks@xxxxxxxxx>]

If I set FCEDIT="zed -h" and then edit the previous command with "fc -1" then after pressing "^X^S" to run the accept-line widget and save the changes, I find that my internal history now only contains 2 lines, and HISTSIZE has been set to 2. Similarly if I try editing a different history file with "zed -h FILE" then after pressing "^X^S", HISTSIZE is set to the number of lines in FILE, and my internal history now only contains that many lines. I can retrieve my history by setting HISTSIZE to a large number, and the entering "fc -R", but I shouldn't have to do this.
Another problem is that if I press "^G" (send-break) inside zed after running "zed -h FILE" then FILE is truncated to a single line.
Apparently there is a similar problem with vared so perhaps they're linked: https://zsh.org/mla/users/2022/msg00100.html