Accept all ignored deletes

If the local permissions are not correct we perform a prohibited move
The move fails with 403 and creates a blacklist entry, but we might get the correct permissions for that file.

In the next sync the we don't retry the move as we have the correct permissions now so we want to restore the original file.
The original file however is now on the blacklist we mark the restoration as ignore and end up in findAndCancelDeletedJob

Fixes: #8837

changelog/unreleased/8837

@@ -0,0 +1,3 @@
+Bugfix: Don't crash if a certain move is undone
+
+https://github.com/owncloud/client/issues/8837

src/libsync/discoveryphase.cpp

@@ -158,34 +158,36 @@ QPair<bool, QByteArray> DiscoveryPhase::findAndCancelDeletedJob(const QString &o
     QByteArray oldEtag;
     auto it = _deletedItem.find(originalPath);
     if (it != _deletedItem.end()) {
-        const SyncInstructions instruction = (*it)->_instruction;
-        if (instruction == CSYNC_INSTRUCTION_IGNORE && (*it)->_type == ItemTypeVirtualFile) {
+        const auto &item = *it;
+        const SyncInstructions instruction = item->_instruction;
+        if (instruction == CSYNC_INSTRUCTION_IGNORE && item->_type == ItemTypeVirtualFile) {
             // re-creation of virtual files count as a delete
+            // restoration after a prohibited move
             // a file might be in an error state and thus gets marked as CSYNC_INSTRUCTION_IGNORE
             // after it was initially marked as CSYNC_INSTRUCTION_REMOVE
             // return true, to not trigger any additional actions on that file that could elad to dataloss
             result = true;
-            oldEtag = (*it)->_etag;
+            oldEtag = item->_etag;
         } else {
             if (!(instruction == CSYNC_INSTRUCTION_REMOVE
                     // re-creation of virtual files count as a delete
-                    || ((*it)->_type == ItemTypeVirtualFile && instruction == CSYNC_INSTRUCTION_NEW)
-                    || ((*it)->_isRestoration && instruction == CSYNC_INSTRUCTION_NEW)))
-            {
+                    || (item->_type == ItemTypeVirtualFile && instruction == CSYNC_INSTRUCTION_NEW)
+                    || (item->_isRestoration && instruction & (CSYNC_INSTRUCTION_NEW | CSYNC_INSTRUCTION_IGNORE)))) {
                 qCWarning(lcDiscovery) << "OC_ENFORCE(FAILING)" << originalPath;
                 qCWarning(lcDiscovery) << "instruction == CSYNC_INSTRUCTION_REMOVE" << (instruction == CSYNC_INSTRUCTION_REMOVE);
-                qCWarning(lcDiscovery) << "((*it)->_type == ItemTypeVirtualFile && instruction == CSYNC_INSTRUCTION_NEW)"
-                                       << ((*it)->_type == ItemTypeVirtualFile && instruction == CSYNC_INSTRUCTION_NEW);
-                qCWarning(lcDiscovery) << "((*it)->_isRestoration && instruction == CSYNC_INSTRUCTION_NEW))"
-                                       << ((*it)->_isRestoration && instruction == CSYNC_INSTRUCTION_NEW);
+                qCWarning(lcDiscovery) << "(item->_type == ItemTypeVirtualFile && instruction == CSYNC_INSTRUCTION_NEW)"
+                                       << (item->_type == ItemTypeVirtualFile && instruction == CSYNC_INSTRUCTION_NEW);
+                qCWarning(lcDiscovery) << "(item->_isRestoration && instruction & (CSYNC_INSTRUCTION_NEW | CSYNC_INSTRUCTION_IGNORE)"
+                                       << (item->_isRestoration && instruction & (CSYNC_INSTRUCTION_NEW | CSYNC_INSTRUCTION_IGNORE);
                 qCWarning(lcDiscovery) << "instruction" << instruction;
-                qCWarning(lcDiscovery) << "(*it)->_type" << (*it)->_type;
-                qCWarning(lcDiscovery) << "(*it)->_isRestoration " << (*it)->_isRestoration;
+                qCWarning(lcDiscovery) << "item->_type" << item->_type;
+                qCWarning(lcDiscovery) << "item->_isRestoration " << item->_isRestoration;
+                qCWarning(lcDiscovery) << "item->_remotePerm" << item->_remotePerm;
                 OC_ENFORCE(false);
             }
-            (*it)->_instruction = CSYNC_INSTRUCTION_NONE;
+            item->_instruction = CSYNC_INSTRUCTION_NONE;
             result = true;
-            oldEtag = (*it)->_etag;
+            oldEtag = item->_etag;
         }
         _deletedItem.erase(it);
     }