tdf#114550 recognize sym key & init vec as valid f/ decrypt

Otherwise package code would _only_ try to decrypt for salt and
iteration count present, which does not make sense for gpg.

Change-Id: Ie366f086a3c14d6b54b91b4edee8cfef1a42c44b
Reviewed-on: https://gerrit.libreoffice.org/47782Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

package/source/zipapi/XUnbufferedStream.cxx

@@ -78,7 +78,10 @@ XUnbufferedStream::XUnbufferedStream(
     if (mnZipSize < 0)
         throw ZipIOException("The stream seems to be broken!");
 
-    bool bHaveEncryptData = rData.is() && rData->m_aSalt.getLength() && rData->m_aInitVector.getLength() && rData->m_nIterationCount != 0;
+    bool bHaveEncryptData = rData.is() && rData->m_aInitVector.getLength() &&
+        ((rData->m_aSalt.getLength() && rData->m_nIterationCount != 0)
+         ||
+         rData->m_aKey.getLength());
     bool bMustDecrypt = nStreamMode == UNBUFF_STREAM_DATA && bHaveEncryptData && bIsEncrypted;
 
     if ( bMustDecrypt )