.htaccess conditions: https issue - .htaccess

Question

A while ago, I asked a question about some .htaccess rules.
Somebody was really kind and gave me the following:
RewriteEngine On
RewriteBase /
# Force https and non-www
RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]
# Redirect /index.htm to /home and avoids infinite redirect loop
RewriteCond %{THE_REQUEST} \s/index\.htm\s [NC]
RewriteRule ^ /home [R=301,L]
# Rewrite (internally) /home to /index.htm
RewriteRule ^home$ /index.htm [L]
# Redirect (if not an existing file) to /index.htm (which will after redirect to /home)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ /index.htm [R=301,L]
I thought it worked perfectly fine, but I have some issues:
https://example.com/
https://example.com/home
https://example.com/index.htm
https://www.example.com/
https://www.example.com/home
https://www.example.com/index.htm
- all variants redirecting to https://example.com/home working fine
http://example.com/ -> https://home (in Chrome) / error (in Firefox)
http://example.com/home -> https://home (in Chrome) / error (in Firefox)
http://example.com/index.htm -> https://index.htm
http://www.example.com/ -> error
http://www.example.com/home -> https://home (in Chrome) / error (in Firefox)
http://www.example.com/index.htm -> https://index.htm
- not working at all
I think it is maybe caused by the [L] flags, but I can not imagine how to solve this problem.
Thanks for your help!

Answer 1

There is a problem is in your first rule because you are attempting to capture value from a RewriteCond after OR clause.
You can use these rules:
RewriteEngine On
RewriteBase /
# Force https and non-www
RewriteCond %{HTTP_HOST} ^www\. [NC,OR]
RewriteCond %{HTTPS} off
RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L,NE]
# Redirect /index.htm to /home and avoids infinite redirect loop
RewriteCond %{THE_REQUEST} \s/index\.htm\s [NC]
RewriteRule ^ /home [R=301,L]
# Rewrite (internally) /home to /index.htm
RewriteRule ^home/?$ /index.htm [L,NC]
# Redirect (if not an existing file) to /index.htm (which will after redirect to /home)
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ /home [R=301,L]
Make sure to clear your browser cache before testing this change.