handle NEW/NEW conflicts by being real conflicts

NEW/NEW conflicts could sometime be ignored and replaced by update
metadata instructions

we stop doing this and handle them like any other conflicts

that would cause more download from the server

those conflicts would be solved automatically in case this is not a real
conflict but the client was missing the server reply with the updated
metadata

will enable more changes to improve MOVE detection from server side

Signed-off-by: Matthieu Gallien <matthieu.gallien@nextcloud.com>

src/libsync/discovery.cpp

@@ -1595,7 +1595,7 @@ void ProcessDirectoryJob::processFileConflict(const SyncFileItemPtr &item, Proce
     // If there's no content hash, use heuristics
     if (serverEntry.checksumHeader.isEmpty()) {
         // If the size or mtime is different, it's definitely a conflict.
-        bool isConflict = (serverEntry.size != localEntry.size) || (serverEntry.modtime != localEntry.modtime);
+        bool isConflict = (serverEntry.size != localEntry.size) || (serverEntry.modtime != localEntry.modtime) || (dbEntry.isValid() && dbEntry._modtime != localEntry.modtime && serverEntry.modtime == localEntry.modtime);
 
         // It could be a conflict even if size and mtime match!
         //

test/testchunkingng.cpp

@@ -328,35 +328,22 @@ private slots:
         fakeFolder.localModifier().insert("A/a0", size);
         QVERIFY(!fakeFolder.syncOnce()); // error: abort!
 
-        // Now the next sync gets a NEW/NEW conflict and since there's no checksum
-        // it just becomes a UPDATE_METADATA
-        auto checkEtagUpdated = [&](SyncFileItemVector &items) {
-            QCOMPARE(items.size(), 1);
-            QCOMPARE(items[0]->_file, QLatin1String("A"));
-            SyncJournalFileRecord record;
-            QVERIFY(fakeFolder.syncJournal().getFileRecord(QByteArray("A/a0"), &record));
-            QCOMPARE(record._etag, fakeFolder.remoteModifier().find("A/a0")->etag);
-        };
-        auto connection = connect(&fakeFolder.syncEngine(), &SyncEngine::aboutToPropagate, checkEtagUpdated);
         QVERIFY(fakeFolder.syncOnce());
-        disconnect(connection);
         QCOMPARE(nGET, 0);
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
 
-
         // Test 2: modified file upload aborted
+        nGET = 0;
         fakeFolder.localModifier().appendByte("A/a0");
         QVERIFY(!fakeFolder.syncOnce()); // error: abort!
 
         // An EVAL/EVAL conflict is also UPDATE_METADATA when there's no checksums
-        connection = connect(&fakeFolder.syncEngine(), &SyncEngine::aboutToPropagate, checkEtagUpdated);
         QVERIFY(fakeFolder.syncOnce());
-        disconnect(connection);
-        QCOMPARE(nGET, 0);
+        QCOMPARE(nGET, 1);
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
 
-
         // Test 3: modified file upload aborted, with good checksums
+        nGET = 0;
         fakeFolder.localModifier().appendByte("A/a0");
         QVERIFY(!fakeFolder.syncOnce()); // error: abort!
 
@@ -365,12 +352,11 @@ private slots:
         fakeFolder.remoteModifier().find("A/a0")->checksums = moveChecksumHeader;
 
         QVERIFY(fakeFolder.syncOnce());
-        disconnect(connection);
         QCOMPARE(nGET, 0); // no new download, just a metadata update!
         QCOMPARE(fakeFolder.currentLocalState(), fakeFolder.currentRemoteState());
 
-
         // Test 4: New file, that gets deleted locally before the next sync
+        nGET = 0;
         fakeFolder.localModifier().insert("A/a3", size);
         QVERIFY(!fakeFolder.syncOnce()); // error: abort!
         fakeFolder.localModifier().remove("A/a3");

test/testsyncengine.cpp

@@ -432,7 +432,7 @@ private slots:
 
         QTest::newRow("Same mtime, but no server checksum -> ignored in reconcile")
             << true << QByteArray()
-            << 0;
+            << 1;
 
         QTest::newRow("Same mtime, weak server checksum differ -> downloaded")
             << true << QByteArray("Adler32:bad")