Read all database attachments even if duplicated

* Fixes #3048
* Certain programs that read/write KDBX4 files do not consolidate duplicate attachments into a single binary. This is against the KDBX4 specification. This change ensures KeePassXC will at least read the database in its entirety and not lose information. Upon saving the database in KeePassXC, the duplicate attachment binaries will be reduced to single binaries per the specification.

src/format/Kdbx4Reader.cpp

@@ -35,7 +35,7 @@ bool Kdbx4Reader::readDatabaseImpl(QIODevice* device,
 {
     Q_ASSERT(m_kdbxVersion == KeePass2::FILE_VERSION_4);
 
-    m_binaryPoolInverse.clear();
+    m_binaryPool.clear();
 
     if (hasError()) {
         return false;
@@ -273,11 +273,7 @@ bool Kdbx4Reader::readInnerHeaderField(QIODevice* device)
             return false;
         }
         auto data = fieldData.mid(1);
-        if (m_binaryPoolInverse.contains(data)) {
-            qWarning("Skipping duplicate binary record");
-            break;
-        }
-        m_binaryPoolInverse.insert(data, QString::number(m_binaryPoolInverse.size()));
+        m_binaryPool.insert(QString::number(m_binaryPool.size()), data);
         break;
     }
     }
@@ -422,17 +418,5 @@ QVariantMap Kdbx4Reader::readVariantMap(QIODevice* device)
  */
 QHash<QString, QByteArray> Kdbx4Reader::binaryPool() const
 {
-    QHash<QString, QByteArray> binaryPool;
-    for (auto it = m_binaryPoolInverse.cbegin(); it != m_binaryPoolInverse.cend(); ++it) {
-        binaryPool.insert(it.value(), it.key());
-    }
-    return binaryPool;
-}
-
-/**
- * @return mapping from binary data to attachment keys
- */
-QHash<QByteArray, QString> Kdbx4Reader::binaryPoolInverse() const
-{
-    return m_binaryPoolInverse;
+    return m_binaryPool;
 }

src/format/Kdbx4Reader.h

@@ -34,7 +34,6 @@ class Kdbx4Reader : public KdbxReader
                           const QByteArray& headerData,
                           QSharedPointer<const CompositeKey> key,
                           Database* db) override;
-    QHash<QByteArray, QString> binaryPoolInverse() const;
     QHash<QString, QByteArray> binaryPool() const;
 
 protected:
@@ -44,7 +43,7 @@ class Kdbx4Reader : public KdbxReader
     bool readInnerHeaderField(QIODevice* device);
     QVariantMap readVariantMap(QIODevice* device);
 
-    QHash<QByteArray, QString> m_binaryPoolInverse;
+    QHash<QString, QByteArray> m_binaryPool;
 };
 
 #endif // KEEPASSX_KDBX4READER_H