Adapt code to deal with case-insensitivity through realpath and renames

Author: schlessera

features/core-update.feature

@@ -246,6 +246,25 @@ Feature: Update WordPress core
       File removed: wp-content
       """
 
+    When I run `wp option add str_opt 'bar'`
+    Then STDOUT should not be empty
+    When I run `wp post create --post_title='Test post' --porcelain`
+    Then STDOUT should be a number
+
+  Scenario: Make sure files are cleaned up with mixed case
+    Given a WP install
+    And I try `wp theme install twentytwenty --activate`
+
+    When I run `wp core update --version=5.8 --force`
+    Then the wp-includes/Requests/Transport/cURL.php file should exist
+    Then the wp-includes/Requests/Exception/Transport/cURL.php file should exist
+    Then the wp-includes/Requests/Exception/HTTP/502.php file should exist
+    Then the wp-includes/Requests/IRI.php file should exist
+    Then the wp-includes/Requests/Transport/Curl.php file should not exist
+    Then the wp-includes/Requests/Exception/Transport/Curl.php file should not exist
+    Then the wp-includes/Requests/Exception/Http/Status502.php file should not exist
+    Then the wp-includes/Requests/Iri.php file should not exist
+
     When I run `wp core update --version=5.9-beta1 --force`
     Then the wp-includes/Requests/Transport/cURL.php file should not exist
     Then the wp-includes/Requests/Exception/Transport/cURL.php file should not exist

src/Core_Command.php

@@ -1375,10 +1375,63 @@ private function cleanup_extra_files( $version_from, $version_to, $locale, $inse
 		// Compare the files from the old version and the new version in a case-insensitive manner,
 		// to prevent files being incorrectly deleted on systems with case-insensitive filesystems
 		// when core changes the case of filenames.
-		$files_to_remove = array_diff(
-			array_map( 'strtolower', array_keys( $old_checksums ) ),
-			array_map( 'strtolower', array_keys( $new_checksums ) )
-		);
+		// The main logic for this was taken from the Joomla project and adapted for WP.
+		// See: https://github.com/joomla/joomla-cms/blob/bb5368c7ef9c20270e6e9fcc4b364cd0849082a5/administrator/components/com_admin/script.php#L8158
+
+		$old_filepaths = array_keys( $old_checksums );
+		$new_filepaths = array_keys( $new_checksums );
+
+		$new_filepaths = array_combine( array_map( 'strtolower', $new_filepaths ), $new_filepaths );
+
+		$old_filepaths_to_check = array_diff( $old_filepaths, $new_filepaths );
+
+		foreach ( $old_filepaths_to_check as $old_filepath_to_check ) {
+			$old_realpath = realpath( ABSPATH . $old_filepath_to_check );
+
+			// On Unix without incorrectly cased file.
+			if ( false === $old_realpath ) {
+				continue;
+			}
+
+			$lowercase_old_filepath_to_check = strtolower( $old_filepath_to_check );
+
+			if ( ! array_key_exists( $lowercase_old_filepath_to_check, $new_filepaths ) ) {
+				$files_to_remove[] = $old_filepath_to_check;
+				continue;
+			}
+
+			// We are now left with only the files that are similar from old to new except for their case.
+
+			$old_basename      = basename( $old_realpath );
+			$expected_basename = basename( $new_filepaths[ $lowercase_old_filepath_to_check ] );
+			$new_realpath      = realpath( ABSPATH . $new_filepaths[ $lowercase_old_filepath_to_check ] );
+			$new_basename      = basename( $new_realpath );
+
+			// On Windows or Unix with only the incorrectly cased file.
+			if ( $new_basename !== $expected_basename ) {
+				// Rename the file.
+				rename( ABSPATH . $old_filepath_to_check, ABSPATH . $old_filepath_to_check . '.tmp' );
+				rename( ABSPATH . $old_filepath_to_check . '.tmp', ABSPATH . $new_filepaths[ $lowercase_old_filepath_to_check ] );
+
+				continue;
+			}
+
+			// There might still be an incorrectly cased file on other OS than Windows.
+			if ( basename( $old_filepath_to_check ) === $old_basename ) {
+				// Check if case-insensitive file system, eg on OSX.
+				if ( fileinode( $old_realpath ) === fileinode( $new_realpath ) ) {
+					// Check deeper because even realpath or glob might not return the actual case.
+					if ( ! in_array( $expected_basename, scandir( dirname( $new_realpath ) ), true ) ) {
+						// Rename the file.
+						rename( ABSPATH . $old_filepath_to_check, ABSPATH . $old_filepath_to_check . '.tmp' );
+						rename( ABSPATH . $old_filepath_to_check . '.tmp', ABSPATH . $expected );
+					}
+				} else {
+					// On Unix with both files: Delete the incorrectly cased file.
+					$files_to_remove[] = $old_filepath_to_check;
+				}
+			}
+		}
 
 		if ( ! empty( $files_to_remove ) ) {
 			WP_CLI::log( 'Cleaning up files...' );