QDataStream: do not lose error status while reading containers

Otherwise, the code:

  ds >> s >> hash;

could set the stream status to ReadPastEnd, while deserialization
of the string is failed with ReadCorruptData status.

Proposed solution is to restore a previously latched error status
unconditionally in accordance with QDataStream::setStatus() docs.

Change-Id: Id3a7dccf709b02e5b018efb48d7647ee48fe5124
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/corelib/io/qdatastream.h b/src/corelib/io/qdatastream.h
index e4cd3b3509..e0a9cccdad 100644
--- a/src/corelib/io/qdatastream.h
+++ b/src/corelib/io/qdatastream.h
@@ -363,8 +363,10 @@ Q_OUTOFLINE_TEMPLATE QDataStream &operator>>(QDataStream &in, QHash<Key, T> &has
 
     if (in.status() != QDataStream::Ok)
         hash.clear();
-    if (oldStatus != QDataStream::Ok)
+    if (oldStatus != QDataStream::Ok) {
+        in.resetStatus();
         in.setStatus(oldStatus);
+    }
     return in;
 }
 
@@ -407,8 +409,10 @@ Q_OUTOFLINE_TEMPLATE QDataStream &operator>>(QDataStream &in, QMap<aKey, aT> &ma
     }
     if (in.status() != QDataStream::Ok)
         map.clear();
-    if (oldStatus != QDataStream::Ok)
+    if (oldStatus != QDataStream::Ok) {
+        in.resetStatus();
         in.setStatus(oldStatus);
+    }
     return in;
 }