prefix); $schema = self::inspect_schema($plan); $action = isset($_POST['wpmr_action']) ? sanitize_key(wp_unslash($_POST['wpmr_action'])) : ''; $result = null; $preview = null; $error = ''; if ($action !== '') { check_admin_referer('wpmr_action', 'wpmr_nonce'); try { self::require_safe_schema($schema); if ($action === 'preview') { $preview = self::preview($plan); } elseif ($action === 'execute') { if (empty($_POST['confirm_backup'])) { throw new RuntimeException('Confirm that you have a restorable backup.'); } $approval = self::verify_approval( isset($_POST['approval']) ? wp_unslash($_POST['approval']) : '', $plan ); $result = self::execute($plan, $approval['counts']); } } catch (Throwable $e) { $error = $e->getMessage(); } } echo '

Mojibake Repair

'; echo '

Temporary repair plugin. Keep your backup. Review the preview carefully. Run once, verify the site, then deactivate and delete this plugin.

'; echo '

Database: ' . esc_html(DB_NAME) . ' Prefix: ' . esc_html($wpdb->prefix) . '

'; self::render_schema($schema); if ($error !== '') { echo '

Stopped: ' . esc_html($error) . '

'; } if ($result !== null) { self::render_result($result); } elseif ($preview !== null) { self::render_preview($preview, $plan); } elseif ($action === '') { echo '

Step 1: Preview

'; echo '

This runs SELECT queries only and shows up to ' . self::SAMPLE_LIMIT . ' changed examples per column.

'; echo ''; } echo '

'; } private static function plan($prefix) { if (!preg_match('/\A[A-Za-z0-9_]+\z/', $prefix)) { throw new RuntimeException('The WordPress table prefix is not a safe SQL identifier.'); } return array( $prefix . 'posts' => array('key' => 'ID', 'columns' => array('post_content', 'post_title', 'post_excerpt')), $prefix . 'postmeta' => array('key' => 'meta_id', 'columns' => array('meta_value')), $prefix . 'options' => array('key' => 'option_id', 'columns' => array('option_value')), $prefix . 'comments' => array('key' => 'comment_ID', 'columns' => array('comment_author', 'comment_content')), $prefix . 'commentmeta' => array('key' => 'meta_id', 'columns' => array('meta_value')), $prefix . 'terms' => array('key' => 'term_id', 'columns' => array('name', 'slug')), $prefix . 'term_taxonomy'=> array('key' => 'term_taxonomy_id', 'columns' => array('description')), $prefix . 'users' => array('key' => 'ID', 'columns' => array('display_name')), $prefix . 'usermeta' => array('key' => 'umeta_id', 'columns' => array('meta_value')), ); } private static function inspect_schema($plan) { global $wpdb; $schema = array(); foreach ($plan as $table => $definition) { $row = $wpdb->get_row($wpdb->prepare( 'SELECT TABLE_TYPE, ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA = %s AND TABLE_NAME = %s', DB_NAME, $table ), ARRAY_A); $columns = $wpdb->get_col($wpdb->prepare( 'SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA = %s AND TABLE_NAME = %s', DB_NAME, $table )); $required = array_merge(array($definition['key']), $definition['columns']); $missing = array_values(array_diff($required, $columns)); $exists = is_array($row) && isset($row['TABLE_TYPE']) && $row['TABLE_TYPE'] === 'BASE TABLE'; $engine = $exists && isset($row['ENGINE']) ? $row['ENGINE'] : ''; $schema[$table] = array( 'columns' => $definition['columns'], 'exists' => $exists, 'engine' => $engine, 'missing' => $missing, 'ready' => $exists && empty($missing) && strcasecmp($engine, 'InnoDB') === 0, ); } return $schema; } private static function require_safe_schema($schema) { foreach ($schema as $table => $status) { if (!$status['exists']) { throw new RuntimeException($table . ' is missing or is not a base table.'); } if (!empty($status['missing'])) { throw new RuntimeException($table . ' is missing: ' . implode(', ', $status['missing']) . '.'); } if (strcasecmp($status['engine'], 'InnoDB') !== 0) { throw new RuntimeException($table . ' uses ' . $status['engine'] . ', not InnoDB. Repair was blocked because rollback cannot be guaranteed.'); } } } private static function preview($plan) { global $wpdb; $preview = array('columns' => array(), 'counts' => array(), 'total' => 0, 'serialized' => 0); foreach ($plan as $table => $definition) { foreach ($definition['columns'] as $column) { $table_sql = self::identifier($table); $key_sql = self::identifier($definition['key']); $column_sql = self::identifier($column); $converted = self::conversion($column); $diff = self::difference($column); $id = $table . '.' . $column; $count = (int) $wpdb->get_var("SELECT COUNT(*) FROM {$table_sql} WHERE {$diff}"); self::throw_on_db_error(); $serialized = (int) $wpdb->get_var( "SELECT COUNT(*) FROM {$table_sql} WHERE {$diff} AND (LEFT({$column_sql},2) IN ('a:','O:','s:','i:','d:','b:','C:') OR {$column_sql}='N;')" ); self::throw_on_db_error(); $samples = array(); if ($count > 0) { $limit = self::SAMPLE_LIMIT; $length = self::SAMPLE_LENGTH; $samples = $wpdb->get_results( "SELECT {$key_sql} AS row_id, LEFT({$column_sql},{$length}) AS before_value, LEFT({$converted},{$length}) AS after_value " . "FROM {$table_sql} WHERE {$diff} ORDER BY {$key_sql} ASC LIMIT {$limit}", ARRAY_A ); self::throw_on_db_error(); } $preview['columns'][] = array( 'table' => $table, 'column' => $column, 'count' => $count, 'serialized' => $serialized, 'samples' => $samples, ); $preview['counts'][$id] = $count; $preview['total'] += $count; $preview['serialized'] += $serialized; } } return $preview; } private static function execute($plan, $approved_counts) { global $wpdb; $current = self::preview($plan); if ($current['counts'] !== $approved_counts) { throw new RuntimeException('The candidate counts changed after preview. Generate a fresh preview.'); } if ($wpdb->query('START TRANSACTION') === false) { self::throw_on_db_error(); } $rows = array(); $total = 0; try { foreach ($plan as $table => $definition) { foreach ($definition['columns'] as $column) { $id = $table . '.' . $column; $expected = isset($approved_counts[$id]) ? (int) $approved_counts[$id] : -1; $table_sql = self::identifier($table); $column_sql = self::identifier($column); $converted = self::conversion($column); $diff = self::difference($column); $affected = $wpdb->query("UPDATE {$table_sql} SET {$column_sql}={$converted} WHERE {$diff}"); if ($affected === false) { self::throw_on_db_error(); } if ((int) $affected !== $expected) { throw new RuntimeException('Affected-row count changed while updating ' . $id . '.'); } $rows[] = array('table' => $table, 'column' => $column, 'affected' => (int) $affected); $total += (int) $affected; } } if ($wpdb->query('COMMIT') === false) { self::throw_on_db_error(); } } catch (Throwable $e) { $wpdb->query('ROLLBACK'); throw $e; } return array('rows' => $rows, 'total' => $total); } private static function conversion($column) { $column_sql = self::identifier($column); return "CONVERT(BINARY CONVERT({$column_sql} USING latin1) USING utf8mb4)"; } private static function difference($column) { $column_sql = self::identifier($column); $converted = self::conversion($column); return "NOT (BINARY {$column_sql} <=> BINARY {$converted})"; } private static function identifier($name) { if (!preg_match('/\A[A-Za-z0-9_]+\z/', $name)) { throw new RuntimeException('Unsafe SQL identifier refused.'); } return '`' . $name . '`'; } private static function throw_on_db_error() { global $wpdb; if ($wpdb->last_error !== '') { throw new RuntimeException('Database error: ' . $wpdb->last_error); } } private static function make_approval($counts) { global $wpdb; $payload = wp_json_encode(array( 'user' => get_current_user_id(), 'database' => DB_NAME, 'prefix' => $wpdb->prefix, 'expires' => time() + self::APPROVAL_TTL, 'counts' => $counts, )); $encoded = rtrim(strtr(base64_encode($payload), '+/', '-_'), '='); return $encoded . '.' . hash_hmac('sha256', $encoded, wp_salt('auth')); } private static function verify_approval($token, $plan) { global $wpdb; $parts = explode('.', $token, 2); if (count($parts) !== 2 || !hash_equals(hash_hmac('sha256', $parts[0], wp_salt('auth')), $parts[1])) { throw new RuntimeException('The preview approval is invalid. Generate a fresh preview.'); } $padding = strlen($parts[0]) % 4; $encoded = $parts[0] . ($padding ? str_repeat('=', 4 - $padding) : ''); $payload = json_decode(base64_decode(strtr($encoded, '-_', '+/'), true), true); if (!is_array($payload) || (int) $payload['user'] !== get_current_user_id() || (string) $payload['database'] !== DB_NAME || (string) $payload['prefix'] !== $wpdb->prefix || (int) $payload['expires'] < time() || !isset($payload['counts']) || !is_array($payload['counts'])) { throw new RuntimeException('The preview approval expired or does not match this site. Generate a fresh preview.'); } $expected_ids = array(); foreach ($plan as $table => $definition) { foreach ($definition['columns'] as $column) { $expected_ids[] = $table . '.' . $column; } } if (array_keys($payload['counts']) !== $expected_ids) { throw new RuntimeException('The preview approval does not match the fixed repair plan.'); } $payload['counts'] = array_map('intval', $payload['counts']); return $payload; } private static function render_schema($schema) { echo ''; foreach ($schema as $table => $status) { $state = $status['ready'] ? 'Ready (' . $status['engine'] . ')' : 'Blocked / missing (' . ($status['engine'] ?: 'not found') . ')'; echo ''; } echo '

Core table	Columns	Status
`' . esc_html($table) . '`	`' . esc_html(implode(', ', $status['columns'])) . '`	' . esc_html($state) . '

'; } private static function render_preview($preview, $plan) { echo '

Preview

'; echo '

' . number_format_i18n($preview['total']) . ' differing column values found. Only the samples below will be displayed; the confirmed update covers all counted candidates.

'; echo '

Important: “different” does not prove mojibake. The conversion is not safe to run twice. Correct non-Latin-1 text can also change.

'; if ($preview['serialized'] > 0) { echo '

' . number_format_i18n($preview['serialized']) . ' candidate values look PHP-serialized. SQL conversion can invalidate embedded string lengths. Review these samples carefully.

'; } foreach ($preview['columns'] as $item) { echo '

'; echo '

' . esc_html($item['table'] . '.' . $item['column']) . ' — ' . number_format_i18n($item['count']) . ' differing

'; if ($item['serialized']) { echo '

Serialized-looking: ' . number_format_i18n($item['serialized']) . '

'; } foreach ($item['samples'] as $sample) { echo '

Row ' . esc_html((string) $sample['row_id']) . '

'; echo '

Before	After
' . esc_html((string) $sample['before_value']) . '	' . esc_html((string) $sample['after_value']) . '

'; } echo '

'; } if ($preview['total'] < 1) { echo '

No update is needed.

'; return; } echo '

Step 2: Run once

'; } private static function render_result($result) { echo '

Repair committed successfully. ' . number_format_i18n($result['total']) . ' column values updated.

'; echo ''; foreach ($result['rows'] as $row) { echo ''; } echo '

Table	Column	Affected
`' . esc_html($row['table']) . '`	`' . esc_html($row['column']) . '`	' . number_format_i18n($row['affected']) . '

Now verify the site, then deactivate and delete this plugin.

'; } } WP_Mojibake_Repair_Temporary::init();