zoom_fit does nothing if --zoom fill was passed

[rsekman]

Steps to reproduce

1. Create or obtain a large image file (e.g, this photo of a ship)
2. Open it using feh --zoom fill
3. Press / to call zoom_fit

Expected behaviour: the image is zoomed so as to fit in the window Actual behaviour: the image remains zoomed to fill the window (not all of it is shown; it doesn't fit.)

If --zoom max or -Z is passed, switching between fill and fit works as expected.

Version information:

% (feh --version 2> /dev/null ; uname -a)
feh version 3.8
Compile-time switches: curl exif inotify help stat64 verscmp xinerama
Linux naoetsu 5.17.9-arch1-1 #1 SMP PREEMPT Wed, 18 May 2022 17:30:11 +0000 x86_64 GNU/Linux

Script to automatically demonstrate the bugged behaviour

#!/usr/bin/sh
url="https://upload.wikimedia.org/wikipedia/commons/8/82/USS_Johnston_%28DD-557%29_underway_on_27_October_1943_%28NH_63495%29.jpg"
fname=ship.jpg
if [ ! -f $fname ]; then
    wget $url -O $fname
fi

delay=2500

feh --info "echo 'No zoom'" $fname &
sleep 1;
xdotool type --delay $delay \! \* / q
sleep 1;

feh --info "echo '--zoom fill'" --zoom fill $fname &
sleep 1;
xdotool type --delay $delay / \!  q
sleep 1;

feh --info "echo '--zoom max'" --zoom max $fname &
sleep 1;
xdotool type --delay $delay \* \! / q