Non moveable mount points should always be UPDATE+DELETE shareable

Fixes #23536

The new sharing code is much stricter in checking permissions. However
for non moveable mounts the permissions UPDATE+DELETE are not reported
on the mount point.

This is just a quick fix.

* Updated unit tests

lib/private/Share20/Manager.php

@@ -23,6 +23,7 @@
 
 namespace OC\Share20;
 
+use OC\Files\Mount\MoveableMount;
 use OCP\Files\IRootFolder;
 use OCP\Files\NotFoundException;
 use OCP\IUserManager;
@@ -215,8 +216,19 @@ class Manager implements IManager {
 			throw new \InvalidArgumentException('A share requires permissions');
 		}
 
+		/*
+		 * Quick fix for #23536
+		 * Non moveable mount points do not have update and delete permissions
+		 * while we 'most likely' do have that on the storage.
+		 */
+		$permissions = $share->getNode()->getPermissions();
+		$mount = $share->getNode()->getMountPoint();
+		if (!($mount instanceof MoveableMount)) {
+			$permissions |= \OCP\Constants::PERMISSION_DELETE | \OCP\Constants::PERMISSION_UPDATE;
+		}
+
 		// Check that we do not share with more permissions than we have
-		if ($share->getPermissions() & ~$share->getNode()->getPermissions()) {
+		if ($share->getPermissions() & ~$permissions) {
 			$message_t = $this->l->t('Cannot increase permissions of %s', [$share->getNode()->getPath()]);
 			throw new GenericShareException($message_t, $message_t, 404);
 		}

tests/lib/share20/managertest.php

@@ -640,10 +640,21 @@ class ManagerTest extends \Test\TestCase {
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_GROUP, $limitedPermssions, $group0, $user0, $user0, null, null, null), 'A share requires permissions', true];
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_LINK,  $limitedPermssions, null, $user0, $user0, null, null, null), 'A share requires permissions', true];
 
+		$mount = $this->getMock('OC\Files\Mount\MoveableMount');
+		$limitedPermssions->method('getMountPoint')->willReturn($mount);
+
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_USER,  $limitedPermssions, $user2, $user0, $user0, 31, null, null), 'Cannot increase permissions of path', true];
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_GROUP, $limitedPermssions, $group0, $user0, $user0, 17, null, null), 'Cannot increase permissions of path', true];
 		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_LINK,  $limitedPermssions, null, $user0, $user0, 3, null, null), 'Cannot increase permissions of path', true];
 
+		$nonMoveableMountPermssions = $this->getMock('\OCP\Files\File');
+		$nonMoveableMountPermssions->method('isShareable')->willReturn(true);
+		$nonMoveableMountPermssions->method('getPermissions')->willReturn(\OCP\Constants::PERMISSION_READ);
+		$nonMoveableMountPermssions->method('getPath')->willReturn('path');
+
+		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_USER,  $nonMoveableMountPermssions, $user2, $user0, $user0, 11, null, null), 'Cannot increase permissions of path', false];
+		$data[] = [$this->createShare(null, \OCP\Share::SHARE_TYPE_GROUP, $nonMoveableMountPermssions, $group0, $user0, $user0, 11, null, null), 'Cannot increase permissions of path', false];
+
 		$rootFolder = $this->getMock('\OCP\Files\Folder');
 		$rootFolder->method('isShareable')->willReturn(true);
 		$rootFolder->method('getPermissions')->willReturn(\OCP\Constants::PERMISSION_ALL);