Merge remote-tracking branch 'origin/5.8' into 5.9

Conflicts:
	configure.json
	mkspecs/win32-icc/qmake.conf

Change-Id: Ibf40546b024d644c7d9ed490bee15b82597f4d3f

2 files changed, 6 insertions, 1 deletions

diff --git a/src/corelib/io/qfiledevice.cpp b/src/corelib/io/qfiledevice.cpp
index 20cfa5bdaf..ce9c8275ce 100644
--- a/src/corelib/io/qfiledevice.cpp
+++ b/src/corelib/io/qfiledevice.cpp
@@ -328,6 +328,9 @@ void QFileDevice::close()
     d->lastWasWrite = false;
     d->writeBuffer.clear();
 
+    // reset cached size
+    d->cachedSize = 0;
+
     // keep earlier error from flush
     if (d->fileEngine->close() && flushed)
         unsetError();
diff --git a/src/corelib/io/qsettings_mac.cpp b/src/corelib/io/qsettings_mac.cpp
index dcaefd1613..e4631bad12 100644
--- a/src/corelib/io/qsettings_mac.cpp
+++ b/src/corelib/io/qsettings_mac.cpp
@@ -269,8 +269,10 @@ static QVariant qtValue(CFPropertyListRef cfvalue)
 
         // Fast-path for QByteArray, so that we don't have to go
         // though the expensive and lossy conversion via UTF-8.
-        if (!byteArray.startsWith('@'))
+        if (!byteArray.startsWith('@')) {
+            byteArray.detach();
             return byteArray;
+        }
 
         const QString str = QString::fromUtf8(byteArray.constData(), byteArray.size());
         return QSettingsPrivate::stringToVariant(str);