id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	mlocked
13013	Correct plist.cpp ParseBinaryDate processing	Gary Buhrmaster <gary.buhrmaster@…>	Stuart Auchterlonie	"Correct plist.cpp ParseBinaryDate processing

gcc correctly warns about a bare time.addMSecs (it returns a QTime):

{{{
plist.cpp: In member function ‘QVariant PList::ParseBinaryDate(quint8*)’:
plist.cpp:467:30: warning: ignoring return value of ‘QTime QTime::addMSecs(int) const’, declared with attribute warn_unused_result [-Wunused-result]
     time.addMSecs(msec % 1000);
                              ^
In file included from /usr/include/qt5/QtCore/QDateTime:1:0,
                 from plist.cpp:32:
/usr/include/qt5/QtCore/qdatetime.h:178:11: note: declared here
     QTime addMSecs(int ms) const Q_REQUIRED_RESULT;
           ^~~~~~~~
}}}


If I understand the code correctly, the intent is to add in the msec offset value into the converted time, with the gyrations needed due to the limitation of the older QDateTime fromTime_t member (seconds only).

Note that in Qt 5.8, QDateTime::fromTime_t is depcrecated, and since Qt 5.2, a new function QDateTime::fromMSecsSinceEpoch exists that appears to do what was originally desired.

Kill the warning (bug), and prepare for the future, with the following proposed patch:

WARNING: Compile tested only (caveat emptor).

{{{
diff --git a/mythtv/libs/libmythbase/plist.cpp b/mythtv/libs/libmythbase/plist.cpp
index c21a776..9aba9b0 100644
--- a/mythtv/libs/libmythbase/plist.cpp
+++ b/mythtv/libs/libmythbase/plist.cpp
@@ -459,16 +459,13 @@ QVariant PList::ParseBinaryDate(quint8 *data)
     quint64 count = GetBinaryCount(&data);
     if (count != 3)
         return result;
 
     convert_float(data, 8);
     quint64 msec = *((double*)data) * 1000.0f;
-    result = QDateTime::fromTime_t(msec / 1000);
-    QTime time = result.time();
-    time.addMSecs(msec % 1000);
-    result.setTime(time);
+    result = QDateTime::fromMSecsSinceEpoch(msec, Qt::UTC);
     LOG(VB_GENERAL, LOG_DEBUG, LOC + QString(""Date: %1"").arg(result.toString(Qt::ISODate)));
     return QVariant(result);
 }
 
 QVariant PList::ParseBinaryData(quint8 *data)
 {
}}}

"	Patch - Bug Fix	closed	minor	29.0	MythTV - General	Master Head	medium	fixed			0