Handle 4 byte database encodings, max key length 191 chars

core/Migrations/Version20170526104128.php

@@ -12,25 +12,48 @@
 class Version20170526104128 implements ISchemaMigration {
 
 	public function changeSchema(Schema $schema, array $options) {
+		// Get the table
 		$prefix = $options['tablePrefix'];
 		$table = $schema->getTable("{$prefix}account_terms");
+
 		// Check column length
-		if($table->getColumn('term')->getLength() === 255) {
+		if($table->getColumn('term')->getLength() === 191) {
 			// we don't need to adjust it
 			return;
 		}
 
 		// Need to shorten the column by one character
-		// Check if we have any terms taking up the full 256 chars (unlikely)
+		// Check if we have any terms taking up 192 or more chars (unlikely)
 
 		/** @var IDBConnection $db */
 		$db = \OC::$server->getDatabaseConnection();
+
+
 		$qb = $db->getQueryBuilder();
-		$qb->delete('account_terms')
-			->where($qb->expr()->gte($qb->expr()->length('term'), new Literal(256)));
-		$qb->execute();
+		$qb->select(['id', 'term'])
+			->from('account_terms')
+			->where($qb->expr()->gte($qb->expr()->length('term'), new Literal(192)));
+		$results = $qb->execute();
+
+		// Now shorten these terms
+		$db->beginTransaction();
+		while($longTerm = $results->fetch()) {
+			$qb->update('account_terms')
+				->where($qb->expr()->eq('id', $qb->createNamedParameter($longTerm['id'])))
+				->set('term', $qb->createNamedParameter($this->trimTerm($longTerm['term'])))
+				->execute();
+		}
+		$db->commit();
 
 		// Now update the column length
-		$table->getColumn('term')->setLength(255);
+		$table->getColumn('term')->setLength(191);
     }
+
+	/**
+	 * @param $longTerm
+	 * @return string the shortened string ready for the new db column
+	 */
+    public function trimTerm($longTerm) {
+		return (string) substr($longTerm, 0, 191);
+	}
 }

lib/private/User/User.php

@@ -456,10 +456,10 @@ public function getSearchTerms() {
 	 * @since 10.0.1
 	 */
 	public function setSearchTerms(array $terms) {
-		// Check length of terms
-		$terms = array_filter($terms, function($term) {
-			return strlen($term) <= 255;
-		});
+		// Check length of terms, cut if too long
+		$terms = array_map(function($term) {
+			return substr($term, 0, 191);
+		}, $terms);
 		$this->mapper->setTermsForAccount($this->account->getId(), $terms);
 	}
 }

tests/lib/User/UserTest.php

@@ -337,7 +337,7 @@ public function testSettingAccountTerms(array $terms, array $expected) {
 	public function setTermsData() {
 		return [
 			'normal terms' => [['term1'], ['term1']],
-			'too long terms' => [['term1', str_repeat(".", 300)], ['term1']]
+			'too long terms' => [['term1', str_repeat(".", 192)], ['term1']]
 		];
 	}