Combine mod_rewrite rules - apache

Question

In my .htaccess I've got the usual rewrite rules but I need to add a HTTP to HTTPS rule. If I put the new rule after the existing rules it does not work but putting it before works but then I suspect the vanilla WordPress code does not work.
I've put the rules together by adding the last two lines of the second rule to the end of the first one but that does not work either. I'm not sure what I'm doing!
What is the best way to combine these two?
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://127.0.0.1/$1 [R,L]
</IfModule>

Answer 1

The ruleset that's responsible for ensuring https is doing an external redirect, while the other one (wordpress) is doing internal rewrites.
It's often a good practice to first put the external redirects (if they don't depend on any previous internal rewrite).
Note the L flag:
The [L] flag causes mod_rewrite to stop processing the rule set. In most contexts, this means that if the rule matches, no further rules will be processed. This corresponds to the last command in Perl, or the break command in C. Use this flag to indicate that the current rule should be applied immediately without considering further rules.
If you put wordpress rewrite rules before the https ruleset, the rewrite engine will never get to the second ruleset. That's because of the L flag that instructs the rewrite engine to stop processing of any other rules. This reason aside, you don't want to rewrite the request to wordpress' index.php and then ensure that it's https using an external redirect (R flag), right?
So, you might want to try this:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteBase /
# HTTPS:
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://127.0.0.1/$1 [R,L]
# WordPress:
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
Few final notes:
You only need one RewriteEngine on and one IfModule.
It's better to use a 301 redirect for https and www redirects. (R=301)