Vfs: Improve sync protocol entries for actions

Creating a new virtual file and replacing a file with a virtual one now
have their own text in the protocol, not just "Downloaded".

To do this, the SyncFileItem type is kept as
ItemTypeVirtualFileDehydration for these actions. Added new code to
ensure the type isn't written to the database.

While looking at this, I've also added documentation on SyncFileItem's
_file, _renameTarget, _originalFile and destination() because some of
the semantics weren't clear.

src/libsync/progressdispatcher.cpp

@@ -29,7 +29,13 @@ QString Progress::asResultString(const SyncFileItem &item)
     case CSYNC_INSTRUCTION_NEW:
     case CSYNC_INSTRUCTION_TYPE_CHANGE:
         if (item._direction != SyncFileItem::Up) {
-            return QCoreApplication::translate("progress", "Downloaded");
+            if (item._type == ItemTypeVirtualFile) {
+                return QCoreApplication::translate("progress", "Virtual file created");
+            } else if (item._type == ItemTypeVirtualFileDehydration) {
+                return QCoreApplication::translate("progress", "Replaced by virtual file");
+            } else {
+                return QCoreApplication::translate("progress", "Downloaded");
+            }
         } else {
             return QCoreApplication::translate("progress", "Uploaded");
         }

src/libsync/propagatedownload.cpp

@@ -427,11 +427,13 @@ void PropagateDownloadFile::startAfterIsEncryptedIsChecked()
         }
 
         qCDebug(lcPropagateDownload) << "dehydrating file" << _item->_file;
-        _item->_type = ItemTypeVirtualFile; // Needed?
         vfs->dehydratePlaceholder(*_item);
         propagator()->_journal->deleteFileRecord(_item->_originalFile);
-        if (!_item->_renameTarget.isEmpty())
-            _item->_file = _item->_renameTarget;
+        // NOTE: This is only done because other rename-like ops also adjust _file, even though
+        // updateMetadata() will store at destination() anyway. Doing this may not be necessary
+        // but maybe it has an effect on reporting (destination() and moves aren't handled
+        // consistently everywhere)
+        _item->_file = _item->destination();
         updateMetadata(false);
         return;
     }

src/libsync/syncfileitem.cpp

@@ -29,7 +29,14 @@ SyncJournalFileRecord SyncFileItem::toSyncJournalFileRecordWithInode(const QStri
     SyncJournalFileRecord rec;
     rec._path = destination().toUtf8();
     rec._modtime = _modtime;
+
+    // Some types should never be written to the database when propagation completes
     rec._type = _type;
+    if (rec._type == ItemTypeVirtualFileDownload)
+        rec._type = ItemTypeFile;
+    if (rec._type == ItemTypeVirtualFileDehydration)
+        rec._type = ItemTypeVirtualFile;
+
     rec._etag = _etag;
     rec._fileId = _fileId;
     rec._fileSize = _size;

src/libsync/syncfileitem.h

@@ -196,15 +196,30 @@ public:
     }
 
     // Variables useful for everybody
+
+    /** The syncfolder-relative filesystem path that the operation is about
+     *
+     * For rename operation this is the rename source and the target is in _renameTarget.
+     */
     QString _file;
-    // for renames: the name _file should be renamed to
-    // for dehydrations: the name _file should become after dehydration (like adding a suffix)
+
+    /** for renames: the name _file should be renamed to
+     * for dehydrations: the name _file should become after dehydration (like adding a suffix)
+     * otherwise empty. Use destination() to find the sync target.
+     */
     QString _renameTarget;
 
+    /** The db-path of this item.
+     *
+     * This can easily differ from _file and _renameTarget if parts of the path were renamed.
+     */
+    QString _originalFile;
+
     /// Whether there's end to end encryption on this file.
     /// If the file is encrypted, the _encryptedFilename is
     /// the encrypted name on the server.
     QString _encryptedFileName;
+
     ItemType _type BITFIELD(3);
     Direction _direction BITFIELD(3);
     bool _serverHasIgnoredFiles BITFIELD(1);
@@ -234,7 +249,6 @@ public:
 
     // Variables used by the propagator
     csync_instructions_e _instruction = CSYNC_INSTRUCTION_NONE;
-    QString _originalFile; // as it is in the csync tree
     time_t _modtime = 0;
     QByteArray _etag;
     quint64 _size = 0;

test/testsyncvirtualfiles.cpp

@@ -678,9 +678,11 @@ private slots:
         QVERIFY(isDehydrated("A/a1"));
         QVERIFY(hasDehydratedDbEntries("A/a1"));
         QVERIFY(itemInstruction(completeSpy, "A/a1.nextcloud", CSYNC_INSTRUCTION_SYNC));
+        QCOMPARE(findItem(completeSpy, "A/a1.nextcloud")->_type, ItemTypeVirtualFileDehydration);
         QVERIFY(isDehydrated("A/a2"));
         QVERIFY(hasDehydratedDbEntries("A/a2"));
         QVERIFY(itemInstruction(completeSpy, "A/a2.nextcloud", CSYNC_INSTRUCTION_SYNC));
+        QCOMPARE(findItem(completeSpy, "A/a2.nextcloud")->_type, ItemTypeVirtualFileDehydration);
 
         QVERIFY(!fakeFolder.currentLocalState().find("B/b1"));
         QVERIFY(!fakeFolder.currentRemoteState().find("B/b1"));