Fix settings.php written to wrong directory when core/ is a symlink, fixes #38

[rfay]

Problem

This project places the Drupal git clone at repos/drupal/ and symlinks web/core -> ../repos/drupal/core/. PHP resolves symlinks when computing __DIR__, realpath(), and chdir('..'), so several places in Drupal's installer compute repos/drupal/ as the application root instead of web/. The result: settings.php is written to repos/drupal/sites/default/ instead of web/sites/default/, DDEV's settings.ddev.php is never loaded, the web installer prompts for database credentials it should already know, and drush appends database credentials to settings.php unnecessarily.

Root causes and fixes

Three files in Drupal core needed patching, each applied from repos/drupal/ (not through web/core) because GNU patch 2.7+ refuses to traverse symlinks.

The key discriminator throughout is is_link($path . '/core'): in repos/drupal/, core/ is a real directory; in web/, core/ is a symlink. When core/ is a real directory, we search ancestor directories for a sibling whose core/ symlink resolves to the same real path.

core/install.php
chdir('..') from inside the symlinked core/ directory sets CWD to repos/drupal/. All relative paths (including './' . $site_path . '/settings.php' in install.core.inc) then resolve under repos/drupal/. Fix: use $_SERVER['SCRIPT_FILENAME'] (set by nginx to the unresolved docroot path) to compute $root_path, then call chdir($root_path) to correct CWD.

core/includes/install.core.inc
install_begin_request() calls Settings::initialize(dirname(__DIR__, 2), ...). __DIR__ resolves via the real filesystem path to repos/drupal/core/includes, so Settings::initialize() looks for settings.php in repos/drupal/sites/default/ and finds nothing — causing the web installer to prompt for database config and drush to write credentials into settings.php. In web context, use $_SERVER['DOCUMENT_ROOT']. In CLI context (drush), detect that core/ is a real directory and search ancestor directories for the web root.

core/lib/Drupal/Core/DrupalKernel.php
guessApplicationRoot() uses __DIR__ for the same reason. Same fix: DOCUMENT_ROOT for web context, ancestor directory search for CLI.

Testing with DDEV

Requirements: DDEV installed.

mkdir ~/tmp/drupal-test && cd ~/tmp/drupal-test
ddev config --project-type=drupal12 --docroot=web
ddev start
ddev composer create-project \
  --repository='{"url":"git@github.com:rfay/drupal-core-development-project","type":"vcs"}' \
  --stability=dev \
  "joachim-n/drupal-core-development-project:dev-20260429_rfay_use_correct_docroot"

Test 1 — drush install:

ddev composer require drush/drush
ddev drush site:install standard --yes --account-name=admin --account-pass=admin

Expected:

• Install completes successfully
• settings.php exists only at web/sites/default/settings.php
• Nothing at repos/drupal/sites/default/settings.php
• No database credentials appended to the end of web/sites/default/settings.php

Test 2 — web installer:

Drop the database and remove settings.php to start fresh:

ddev drush sql-drop -y
rm web/sites/default/settings.php
ddev restart   # DDEV recreates settings.php and settings.ddev.php
ddev exec "chmod 777 /var/www/html/web/sites/default && chmod 666 /var/www/html/web/sites/default/settings.php"

Visit https://drupal-test.ddev.site/core/install.php in a browser.

Expected: the installer proceeds language → profile → "Installing Drupal" without prompting for database credentials (DDEV's settings.ddev.php is loaded automatically). After installation completes, settings.php should exist only at web/sites/default/settings.php.

Verify the wrong location is empty:

ls repos/drupal/sites/default/
# Should show only: default.services.yml  default.settings.php
# settings.php must NOT be present

[rpkoller]

i can confirm, the PR in combination with ddev/ddev#8366 fixes #38