fix: allow moving from of non-resharable to other share if the user has delete permissions

Signed-off-by: Robin Appelman <robin@icewind.nl>

Author: icewind1991

apps/dav/lib/Connector/Sabre/SharesPlugin.php

@@ -262,6 +262,14 @@ public function validateMoveOrCopy(string $source, string $target): bool {
 					return true;
 				}
 			}
+
+			// if the share recipient is allow to delete from the share, they are allowed to move the file out of the share
+			// the user moving the file out of the share to their home storage would give them share permissions and allow moving into the share
+			//
+			// since the 2-step move is allowed, we also allow both steps at once
+			if ($sourceNode->isDeletable()) {
+				return true;
+			}
 		}
 
 		throw new Forbidden('You cannot move a non-shareable node into a share');