fix: allow files with 255 characters in filenamefix/allow-255-filenames

Align with Linux length limit instead of arbitrary 250 characters.
Migration should not be too expensive as only the metadata is updated
but no table data is touched.

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

4 files changed, 41 insertions, 6 deletions

diff --git a/build/integration/dav_features/dav-v2.feature b/build/integration/dav_features/dav-v2.feature
index 9eae9a1b5fd..88b9d7c6460 100644
--- a/build/integration/dav_features/dav-v2.feature
+++ b/build/integration/dav_features/dav-v2.feature
@@ -114,7 +114,7 @@ Feature: dav-v2
 		And user "user0" exists
 		And user "user0" has a quota of "10 MB"
 		And As an "user0"
-		When User "user0" uploads file "data/textfile.txt" to "/long-filename-with-250-characters-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.txt"
+		When User "user0" uploads file "data/textfile.txt" to "/long-filename-with-255-characters-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.txt"
 		Then the HTTP status code should be "201"
 
 	Scenario: Uploading a file with a too long filename
@@ -123,7 +123,7 @@ Feature: dav-v2
 		And user "user0" exists
 		And user "user0" has a quota of "10 MB"
 		And As an "user0"
-		When User "user0" uploads file "data/textfile.txt" to "/long-filename-with-251-characters-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.txt"
+		When User "user0" uploads file "data/textfile.txt" to "/long-filename-with-256-characters-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.txt"
 		Then the HTTP status code should be "400"
 
 	Scenario: Create a search query on image
diff --git a/core/Migrations/Version13000Date20170718121200.php b/core/Migrations/Version13000Date20170718121200.php
index 1adbf2f0ea2..e47dd72f7cd 100644
--- a/core/Migrations/Version13000Date20170718121200.php
+++ b/core/Migrations/Version13000Date20170718121200.php
@@ -178,7 +178,8 @@ class Version13000Date20170718121200 extends SimpleMigrationStep {
 			]);
 			$table->addColumn('name', 'string', [
 				'notnull' => false,
-				'length' => 250,
+				// changed from 250 to 255 in Nextcloud 32 to align with operating systems (Version32000Date20250422135900)
+				'length' => 255,
 			]);
 			$table->addColumn('mimetype', Types::BIGINT, [
 				'notnull' => true,
diff --git a/core/Migrations/Version32000Date20250422135900.php b/core/Migrations/Version32000Date20250422135900.php
new file mode 100644
index 00000000000..f0c511c8144
--- /dev/null
+++ b/core/Migrations/Version32000Date20250422135900.php
@@ -0,0 +1,34 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Core\Migrations;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\Migration\Attributes\ModifyColumn;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+/**
+ * Adjust name length to support 255 characters to align with operating systems.
+ *
+ * See also Version13000Date20170718121200
+ */
+#[ModifyColumn(table: 'filecache', name: 'name', description: 'adjust length to maximal supported 255 characters')]
+class Version32000Date20250422135900 extends SimpleMigrationStep {
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$table = $schema->getTable('filecache');
+		$column = $table->getColumn('name');
+		if ($column->getLength() < 255) {
+			$column->setLength(255);
+		}
+
+		return $schema;
+	}
+}
diff --git a/lib/private/Files/FilenameValidator.php b/lib/private/Files/FilenameValidator.php
index b1979789ec8..e07c07a9208 100644
--- a/lib/private/Files/FilenameValidator.php
+++ b/lib/private/Files/FilenameValidator.php
@@ -180,9 +180,9 @@ class FilenameValidator implements IFilenameValidator {
 			throw new InvalidDirectoryException($this->l10n->t('Dot files are not allowed'));
 		}
 
-		// 255 characters is the limit on common file systems (ext/xfs)
-		// oc_filecache has a 250 char length limit for the filename
-		if (isset($filename[250])) {
+		// 255 characters is the limit on common file systems (ext/xfs) and in general on Linux.
+		// this is also the limit of oc_filecache for the filename
+		if (isset($filename[255])) {
 			throw new FileNameTooLongException();
 		}