PHP FastCGI - How PHPRC works

Question

I have a weird situation here in my configuration of Apache. I have decided to use FastCGI and multiple versions of PHP. Below are my configuration files.

If I check phpinfo(); I can see that on domain localhost it is loading php.ini from folder php56. This is OK. What I don't understand, why on domain localhost7 it is loading php.ini from folder php71. I don't change PHPRC somewhere for PHP7, but it is loading different config file. How this works, or why it is loading php.ini from different folder?

If I changed PHPRC to totally different folder, it works also. Is this constant not used, or it is because I'm on Windows (different behaviour)?

<IfModule fcgid_module>
    FcgidInitialEnv PATH "C:/www/xampp/php5.6;C:/WINDOWS/system32;C:/WINDOWS;C:/WINDOWS/System32/Wbem;"
    FcgidInitialEnv SystemRoot "C:/Windows"
    FcgidInitialEnv SystemDrive "C:"
    FcgidInitialEnv TEMP "C:/www/xampp/tmp"
    FcgidInitialEnv TMP "C:/www/xampp/tmp"
    FcgidInitialEnv windir "C:/WINDOWS"
    FcgidIOTimeout 64
    FcgidConnectTimeout 16
    FcgidMaxRequestsPerProcess 1000 
    FcgidMaxProcesses 3
    FcgidMaxRequestLen 8131072
    # Location php.ini:
    FcgidInitialEnv PHPRC "C:/www/xampp/php5.6/"
    FcgidInitialEnv PHP_FCGI_MAX_REQUESTS 1000

    <Files ~ "\.php$">
        Options Indexes FollowSymLinks ExecCGI 
        AddHandler fcgid-script .php
        FcgidWrapper "C:/web/xampp/php5.6/php-cgi.exe" .php
    </Files>
</IfModule>

Virtual hosts config file:

<VirtualHost *:80>
    DocumentRoot "C:/web/xampp/htdocs/"
    ServerName localhost7

    <Directory "C:/web/xampp/htdocs/"> 
        <Files ~ "\.php$"> 
            Options +ExecCGI
            FcgidWrapper "c:/web/xampp/php7.1/php-cgi.exe" .php 
        </Files> 
    </Directory> 
</VirtualHost>
<VirtualHost *:80>
    DocumentRoot "C:/web/xampp/htdocs/"
    ServerName localhost

    <Directory "C:/web/xampp/htdocs/"> 
        <Files ~ "\.php$"> 
            Options +ExecCGI
            FcgidWrapper "c:/web/xampp/php5.6/php-cgi.exe" .php 
        </Files> 
    </Directory> 
</VirtualHost>

Answer 1

I'm so ashamed :(

Please, check your paths twice (or more times), problem is always there. If you check it, I had path to php-cgi.exe C:\web\... but to PHPRC it is C:\www\.... And this is only reason.

And correct php.ini was loaded, because it is default behaviour. Here is order of places, where PHP is searching for php.ini file: http://php.net/manual/en/configuration.file.php