Already installed plugin shows with "Install Now" button on plugin-install.php page

[mapk]

I have the plugin Hello Dolly already installed, just not activated. When I search for that plugin in the "Add New Plugin" plugin-install.php page, it shows up with a button to "Install Now". Shouldn't it detect my installation and show "Installed" or "Activate" instead?

Already installed plugin

But shows as needing to be installed on plugin-install.php

[swissspidy]

I assume the already installed plugin is wp-content/plugins/hello.php, which gets shipped with every WordPress site by default.

On the plugin-install.php screen, Hello Dolly is displayed as not being installed because install_plugin_install_status() checks if the wp-content/plugins/hello-dolly/ directory exists. Obviously it doesn't, because it's just a PHP file. Therefore you're able to install the plugin from WordPress.org.

Technically those are separate plugins that happen to have the same name. It's like having a GitHub checkout from WooCommerce inside wp-content/plugins/woocommerce-master. You can still download it from WordPress.org

[swissspidy]

Duplicate of #29540.

[ocean90]

#49338 was marked as a duplicate.

[SergeyBiryukov]

#49590 was marked as a duplicate.