wordpress@webserver:~/wordpress_n$ diff ./wp-includes/admin-bar.php-orig ./wp-includes/admin-bar.php
290c290
< $blogname = preg_replace( '#^(https?://)?(www.)?#', '', get_home_url() );
---
> $blogname = preg_replace( '#^(https?://)?(master.)?#', '', get_home_url() );
464c464
< $blogname = preg_replace( '#^(https?://)?(www.)?#', '', get_home_url() );
---
> $blogname = preg_replace( '#^(https?://)?(master.)?#', '', get_home_url() );
wordpress@webserver:~/wordpress_n$ diff ./wp-admin/network/site-new.php-orig ./wp-admin/network/site-new.php
83c83
< $newdomain = $domain . '.' . preg_replace( '|^www\.|', '', $current_site->domain );
---
> $newdomain = $domain . '.' . preg_replace( '|^master\.|', '', $current_site->domain );
174c174
< <input name="blog[domain]" type="text" class="regular-text" id="site-address" aria-describedby="site-address-desc" autocapitalize="none" autocorrect="off"/><span class="no-break">.<?php echo preg_replace( '|^www\.|', '', $current_site->domain ); ?></span>
---
> <input name="blog[domain]" type="text" class="regular-text" id="site-address" aria-describedby="site-address-desc" autocapitalize="none" autocorrect="off"/><span class="no-break">.<?php echo preg_replace( '|^master\.|', '', $current_site->domain ); ?></span>
wordpress@webserver:~/wordpress_n$ diff ./wp-content/plugins/multisite-clone-duplicator/include/admin.php-orig ./wp-content/plugins/multisite-clone-duplicator/include/admin.php
300c300
< $newdomain = $domain . '.' . preg_replace( '|^www\.|', '', $current_site->domain );
---
> $newdomain = $domain . '.' . preg_replace( '|^master\.|', '', $current_site->domain );
wordpress@webserver:~/wordpress_n$ diff ./wp-content/plugins/multisite-clone-duplicator/wp-cli/wp-cli-site-duplicate-subcommand.php-orig ./wp-content/plugins/multisite-clone-duplicator/wp-cli/wp-cli-site-duplicate-subcommand.php
110c110
< $newdomain = $base.'.'.preg_replace( '|^www\.|', '', $network->domain );
---
> $newdomain = $base.'.'.preg_replace( '|^master\.|', '', $network->domain );
wordpress@webserver:~/wordpress_n$ diff wp-content/plugins/multisite-clone-duplicator/template/network_admin_duplicate_site.php-orig wp-content/plugins/multisite-clone-duplicator/template/network_admin_duplicate_site.php
31c31
< <input name="site[domain]" type="text" class="large-text" title="<?php echo MUCD_NETWORK_PAGE_DUPLICATE_FIELD_ADDRESS ; ?>" value="<?php echo $data['domain']?>"/><span class="no-break">.<?php echo preg_replace( '|^www\.|', '', $current_site->domain ); ?></span>
---
> <input name="site[domain]" type="text" class="large-text" title="<?php echo MUCD_NETWORK_PAGE_DUPLICATE_FIELD_ADDRESS ; ?>" value="<?php echo $data['domain']?>"/><span class="no-break">.<?php echo preg_replace( '|^master\.|', '', $current_site->domain ); ?></span>