From 796988f735b0e5f1326b1a0f3bf8bdd7dd5cb12d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=B4me=20Chilliet?= <come.chilliet@nextcloud.com>
Date: Fri, 13 Sep 2024 10:00:53 +0200
Subject: [PATCH] fix(shares): Promote reshares into direct shares when share
 is deleted
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Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>
---
 lib/private/Share20/Manager.php | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/lib/private/Share20/Manager.php b/lib/private/Share20/Manager.php
index 4b7b261887297..c6c2bf14e021f 100644
--- a/lib/private/Share20/Manager.php
+++ b/lib/private/Share20/Manager.php
@@ -754,6 +754,7 @@ public function createShare(IShare $share) {
 	 * @param IShare $share
 	 * @return IShare The share object
 	 * @throws \InvalidArgumentException
+	 * @throws GenericShareException
 	 */
 	public function updateShare(IShare $share) {
 		$expirationDateUpdated = false;
@@ -1011,7 +1012,8 @@ protected function deleteChildren(IShare $share) {
 		return $deletedShares;
 	}
 
-	protected function deleteReshares(IShare $share): void {
+	/* Promote reshares into direct shares so that target user keeps access */
+	protected function promoteReshares(IShare $share): void {
 		try {
 			$node = $share->getNode();
 		} catch (NotFoundException) {
@@ -1029,7 +1031,7 @@ protected function deleteReshares(IShare $share): void {
 
 			foreach ($users as $user) {
 				/* Skip share owner */
-				if ($user->getUID() === $share->getShareOwner()) {
+				if ($user->getUID() === $share->getShareOwner() || $user->getUID() === $share->getSharedBy()) {
 					continue;
 				}
 				$userIds[] = $user->getUID();
@@ -1072,8 +1074,13 @@ protected function deleteReshares(IShare $share): void {
 			try {
 				$this->generalCreateChecks($child);
 			} catch (GenericShareException $e) {
-				$this->logger->debug('Delete reshare because of exception '.$e->getMessage(), ['exception' => $e]);
-				$this->deleteShare($child);
+				$this->logger->debug('Promote reshare because of exception '.$e->getMessage(), ['exception' => $e, 'fullId' => $child->getFullId()]);
+				try {
+					$child->setSharedBy($share->getSharedBy());
+					$this->updateShare($child);
+				} catch (GenericShareException|\InvalidArgumentException $e) {
+					$this->logger->warning('Failed to promote reshare because of exception '.$e->getMessage(), ['exception' => $e, 'fullId' => $child->getFullId()]);
+				}
 			}
 		}
 	}
@@ -1103,8 +1110,8 @@ public function deleteShare(IShare $share) {
 
 		$this->dispatcher->dispatchTyped(new ShareDeletedEvent($share));
 
-		// Delete reshares of the deleted share
-		$this->deleteReshares($share);
+		// Promote reshares of the deleted share
+		$this->promoteReshares($share);
 	}