fix: Fixed crash recovery issue (#914)

* Sync position of writeRaf during recovery

* BinaryReader.readFrame return null when frameLength < 8

hive/lib/src/backend/vm/storage_backend_vm.dart

@@ -92,6 +92,7 @@ class StorageBackendVm extends StorageBackend {
       if (_crashRecovery) {
         print('Recovering corrupted box.');
         await writeRaf.truncate(recoveryOffset);
+        await writeRaf.setPosition(recoveryOffset);
         writeOffset = recoveryOffset;
       } else {
         throw HiveError('Wrong checksum in hive file. Box may be corrupted.');

hive/lib/src/binary/binary_reader_impl.dart

@@ -243,13 +243,14 @@ class BinaryReaderImpl extends BinaryReader {
   /// Not part of public API
   Frame? readFrame(
       {HiveCipher? cipher, bool lazy = false, int frameOffset = 0}) {
+    // frame length is stored on 4 bytes
     if (availableBytes < 4) return null;
 
+    // frame length should be at least 8 bytes
     var frameLength = readUint32();
-    if (frameLength < 8) {
-      throw HiveError(
-          'This should not happen. Please open an issue on GitHub.');
-    }
+    if (frameLength < 8) return null;
+
+    // frame is bigger than avaible bytes
     if (availableBytes < frameLength - 4) return null;
 
     var crc = _buffer.readUint32(_offset + frameLength - 8);
@@ -260,6 +261,7 @@ class BinaryReaderImpl extends BinaryReader {
       crc: cipher?.calculateKeyCrc() ?? 0,
     );
 
+    // frame is corrupted or provided chiper is different
     if (computedCrc != crc) return null;
 
     _limitAvailableBytes(frameLength - 8);

hive/test/tests/backend/vm/storage_backend_vm_test.dart

@@ -169,10 +169,13 @@ void main() {
           when(() => lockRaf.lock()).thenAnswer((i) => Future.value(lockRaf));
           when(() => writeRaf.truncate(20))
               .thenAnswer((i) => Future.value(writeRaf));
+          when(() => writeRaf.setPosition(20))
+              .thenAnswer((i) => Future.value(writeRaf));
 
           await backend.initialize(
               TypeRegistryImpl.nullImpl, MockKeystore(), lazy);
           verify(() => writeRaf.truncate(20));
+          verify(() => writeRaf.setPosition(20));
         });
 
         test('recoveryOffset without crash recovery', () async {

hive/test/tests/binary/binary_reader_test.dart

@@ -351,6 +351,39 @@ void main() {
     });
 
     group('.readFrame()', () {
+      final List<Uint8List> nullFramesBytes = [
+        // availableBytes < 4
+        // there is ONLY 3 bytes provided
+        Uint8List.fromList([8, 0, 0]),
+        // frameLength < 8
+        // frame is 7 length
+        Uint8List.fromList([7, 0, 0, 0, 0, 0, 0, 0, 0, 0]),
+        // availableBytes < frameLength - 4
+        // frame is 10 length however ONLY 9 bytes provided
+        Uint8List.fromList([10, 0, 0, 0, 0, 0, 0, 0, 0]),
+        // computedCrc != crc
+        // 0, 0, 0, 0 crc is: 0 and computedCrc is: 274301637
+        Uint8List.fromList([10, 0, 0, 0, 0, 0, 0, 0, 0, 0]),
+      ];
+
+      test('null', () {
+        for (final bytes in nullFramesBytes) {
+          final reader = BinaryReaderImpl(bytes, testRegistry);
+          final frame = reader.readFrame(lazy: false);
+
+          expect(frame, null);
+        }
+      });
+
+      test('null lazy', () {
+        for (final bytes in nullFramesBytes) {
+          final reader = BinaryReaderImpl(bytes, testRegistry);
+          final frame = reader.readFrame(lazy: true);
+
+          expect(frame, null);
+        }
+      });
+
       test('normal', () {
         var frames = framesSetLengthOffset(testFrames, frameBytes);
         var offset = 0;
@@ -397,7 +430,7 @@ void main() {
         }
       });
 
-      test('lazy', () {
+      test('encrypted lazy', () {
         var frames = framesSetLengthOffset(testFrames, frameBytesEncrypted);
         var offset = 0;
         for (var i = 0; i < frames.length; i++) {