[irozum]

Summary

On multisite, the plugin and theme editors only exist in the network admin, and wp-admin/plugin-editor.php / theme-editor.php redirect there without the query string. wp_edit_theme_plugin_file() ran its fatal-error loopback against admin_url(), so the redirect dropped wp_scrape_key and wp_scrape_nonce. No scrape result was printed, and valid PHP edits were reverted with loopback_request_failed.

Changes

• Use network_admin_url() for the plugin and theme editor loopback URLs. On a single site it returns admin_url(), so nothing changes there.

Tests

• Existing plugin tests now expect the network admin editor path (identical on single site).
• Added test_should_send_editor_loopback_to_network_admin_on_multisite, which fails before the fix.
• No theme-specific test was added. The theme and plugin branches share the same loopback code.

Known limitation, not addressed

• A plugin or theme active only on a secondary site isn't flagged, because the loopback hits the main site (see comment 6 on the ticket).

Trac ticket: https://core.trac.wordpress.org/ticket/45755

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Sonnet 5.5
Used for: Implementation, tests, and PR description.

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