From a8355df12ece4fe615e59f82e85439023208420b Mon Sep 17 00:00:00 2001
From: Dillard Blom <dillard.blom@ensembia.com>
Date: Thu, 22 Oct 2026 03:36:46 +0200
Subject: [PATCH] Full restore: tables the restore creates get this
 installation's charset and collation (utf8mb4 on MySQL/MariaDB); test with an
 emoji

---
 lib/Db/DbDumper.php                         | 29 ++++++++++++++++++---
 tests/integration/full-restore-roundtrip.sh |  3 +++
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/lib/Db/DbDumper.php b/lib/Db/DbDumper.php
index b0918f7..6bd3a40 100644
--- a/lib/Db/DbDumper.php
+++ b/lib/Db/DbDumper.php
@@ -159,7 +159,7 @@ final class DbDumper {
 		// everywhere); tables it does not know are left out, as asked.
 		foreach ($missing as $table) {
 			if (isset($manifest['tables'][$table]['schema'])) {
-				$this->db->createSchemaManager()->createTable(self::tableFromStructure($table, $manifest['tables'][$table]['schema']));
+				$this->db->createSchemaManager()->createTable(self::tableFromStructure($table, $manifest['tables'][$table]['schema'], $this->tableOptions()));
 				$report['created'][] = $table;
 			} else {
 				$report['missing'][] = $table;
@@ -319,8 +319,31 @@ final class DbDumper {
 			'foreignKeys' => $foreignKeys];
 	}
 
-	private static function tableFromStructure(string $name, array $structure): \Doctrine\DBAL\Schema\Table {
-		$table = new \Doctrine\DBAL\Schema\Table($name);
+	/**
+	 * Table options for a table the restore creates: those of this installation's own tables.
+	 * On MySQL/MariaDB that is the character set and collation, as Nextcloud's tables have them
+	 * (utf8mb4, so emoji and other 4-byte characters fit); DBAL alone would use 3-byte utf8.
+	 *
+	 * @return array<string, mixed>
+	 * @psalm-suppress UndefinedClass the DBAL classes come with Nextcloud, not with this app
+	 */
+	private function tableOptions(): array {
+		$options = $this->db->createSchemaManager()->createSchemaConfig()->getDefaultTableOptions();
+		if ($this->db->getDatabasePlatform() instanceof \Doctrine\DBAL\Platforms\AbstractMySQLPlatform) {
+			$collation = $this->db->fetchOne('SELECT TABLE_COLLATION FROM information_schema.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = ?',
+				[$this->prefix . 'appconfig']);
+			if (is_string($collation) && $collation !== '') {
+				$options['collation'] = $collation;
+				$options['charset'] = explode('_', $collation, 2)[0];
+				unset($options['collate']);
+			}
+		}
+		return $options;
+	}
+
+	/** @param array<string, mixed> $options table options (see tableOptions()) */
+	private static function tableFromStructure(string $name, array $structure, array $options = []): \Doctrine\DBAL\Schema\Table {
+		$table = new \Doctrine\DBAL\Schema\Table($name, [], [], [], [], $options);
 		foreach ($structure['columns'] as $c) {
 			$table->addColumn($c['name'], $c['type'], array_filter([
 				'length' => $c['length'], 'precision' => $c['precision'], 'scale' => $c['scale'],
diff --git a/tests/integration/full-restore-roundtrip.sh b/tests/integration/full-restore-roundtrip.sh
index ab79807..01b46ce 100755
--- a/tests/integration/full-restore-roundtrip.sh
+++ b/tests/integration/full-restore-roundtrip.sh
@@ -119,6 +119,8 @@ if [ "$DB" != sqlite ]; then
 		|| fail "the mail account does not point at its mailboxes"
 	# Deck installed and then switched off: its tables stay in the database and in the backup
 	run_on ngb-frt-origin app:install deck >/dev/null || fail "install deck on the origin"
+	# a 4-byte character (emoji) in a table the restore has to create: utf8mb4 on MySQL/MariaDB
+	sql origin "insert into oc_deck_boards (title, owner, color, archived, deleted_at, last_modified) values ('Plan 📌', 'frtest', '0087C5', 0, 0, 0)" >/dev/null
 	run_on ngb-frt-origin app:disable deck >/dev/null
 	ok "origin has a synced Mail account and the tables of a disabled app"
 fi
@@ -202,6 +204,7 @@ if [ "$ORIGIN_DBTYPE" != sqlite ] && [ "$DB" != sqlite ] && [ "$LEGACY" = legacy
 	ok "older backup: tables of the disabled app left out, Mail restored"
 elif [ "$ORIGIN_DBTYPE" != sqlite ] && [ "$DB" != sqlite ]; then
 	[ "$(sql restore "select count(*) from information_schema.tables where table_name = 'oc_deck_boards'")" = 1 ] || fail "the tables of the disabled app were not created"
+	[ "$(sql restore "select title from oc_deck_boards")" = "Plan 📌" ] || fail "a 4-byte character did not survive in a created table"
 	[ "$(sql restore "select count(*) from oc_mail_accounts where drafts_mailbox_id is not null")" = 1 ] || fail "the mail account was not restored"
 	[ "$(sql restore "select count(*) from information_schema.table_constraints where constraint_type = 'FOREIGN KEY' and table_name like 'oc_mail_%'")" -gt 0 ] \
 		|| fail "the foreign keys of Mail are missing after the restore"