wp-admin/includes/theme-install.php:195Displays a form to upload themes from zip files.
function install_themes_upload() { ?><p class="install-help"><?php _e( 'If you have a theme in a .zip format, you may install or update it by uploading it here.' ); ?></p><form method="post" enctype="multipart/form-data" class="wp-upload-form" action="<?php echo esc_url( self_admin_url( 'update.php?action=upload-theme' ) ); ?>"> <?php wp_nonce_field( 'theme-upload' ); ?> <label class="screen-reader-text" for="themezip"> <?php /* translators: Hidden accessibility text. */ _e( 'Theme zip file' ); ?> </label> <input type="file" id="themezip" name="themezip" accept=".zip" /> <?php submit_button( _x( 'Install Now', 'theme' ), '', 'install-theme-submit', false ); ?></form> <?php}Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/theme-install.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.