KConfig: preserve the milliseconds component of QDateTime

I stored a file's lastModified() into KConfig, to compare with it
again on next start, and the loss of milliseconds made the code think
the timestamps didn't match, even when they did.

2 files changed, 15 insertions, 6 deletions

diff --git a/autotests/kconfigtest.cpp b/autotests/kconfigtest.cpp
index 6f79f072..6ab50b2f 100644
--- a/autotests/kconfigtest.cpp
+++ b/autotests/kconfigtest.cpp
@@ -66,6 +66,7 @@ static QString homePath()
 #define SIZEENTRY QSize( 10, 20 )
 #define RECTENTRY QRect( 10, 23, 5321, 13 )
 #define DATETIMEENTRY QDateTime( QDate( 2002, 06, 23 ), QTime( 12, 55, 40 ) )
+#define DATETIMEWITHMSENTRY QDateTime( QDate( 2002, 06, 23 ), QTime( 12, 55, 40, 532 ) )
 #define STRINGLISTENTRY (QStringList( "Hello," ) << " World")
 #define STRINGLISTEMPTYENTRY QStringList()
 #define STRINGLISTJUSTEMPTYELEMENT QStringList(QString())
@@ -154,6 +155,7 @@ void KConfigTest::initTestCase()
     cg.writeEntry("sizeEntry", SIZEENTRY);
     cg.writeEntry("dateTimeEntry", DATETIMEENTRY);
     cg.writeEntry("dateEntry", DATETIMEENTRY.date());
+    cg.writeEntry("dateTimeWithMSEntry", DATETIMEWITHMSENTRY);
 
     KConfigGroup ct = cg;
     cg = KConfigGroup(&ct, "Nested Group 1");
@@ -620,10 +622,12 @@ void KConfigTest::testComplex()
     QCOMPARE(sc3.readEntry("pointEntry", QPoint()), POINTENTRY);
     QCOMPARE(sc3.readEntry("sizeEntry", SIZEENTRY), SIZEENTRY);
     QCOMPARE(sc3.readEntry("rectEntry", QRect(1, 2, 3, 4)), RECTENTRY);
-    QCOMPARE(sc3.readEntry("dateTimeEntry", QDateTime()).toString(Qt::ISODate),
-             DATETIMEENTRY.toString(Qt::ISODate));
+    QCOMPARE(sc3.readEntry("dateTimeEntry", QDateTime()).toString(Qt::ISODateWithMs),
+             DATETIMEENTRY.toString(Qt::ISODateWithMs));
     QCOMPARE(sc3.readEntry("dateEntry", QDate()).toString(Qt::ISODate),
              DATETIMEENTRY.date().toString(Qt::ISODate));
+    QCOMPARE(sc3.readEntry("dateTimeWithMSEntry", QDateTime()).toString(Qt::ISODateWithMs),
+             DATETIMEWITHMSENTRY.toString(Qt::ISODateWithMs));
     QCOMPARE(sc3.readEntry("dateTimeEntry", QDate()), DATETIMEENTRY.date());
 }
 
diff --git a/src/core/kconfiggroup.cpp b/src/core/kconfiggroup.cpp
index cc4f8d0c..14cbcab8 100644
--- a/src/core/kconfiggroup.cpp
+++ b/src/core/kconfiggroup.cpp
@@ -27,6 +27,7 @@
 #include <QUrl>
 
 #include <stdlib.h>
+#include <math.h>
 
 class KConfigGroupPrivate : public QSharedData
 {
@@ -325,14 +326,18 @@ QVariant KConfigGroup::convertToQVariant(const char *pKey, const QByteArray &val
         return size;
     }
     case QMetaType::QDateTime: {
-        const auto list = asIntList(value);
-        if (list.count() != 6) {
+        const auto list = asRealList(value);
+        if (list.count() < 6) {
             qCWarning(KCONFIG_CORE_LOG) << errString(pKey, value, aDefault)
                        << formatError(6, list.count());
             return aDefault;
         }
         const QDate date(list.at(0), list.at(1), list.at(2));
-        const QTime time(list.at(3), list.at(4), list.at(5));
+        const qreal totalSeconds = list.at(5);
+        qreal seconds;
+        const qreal fractional = modf(totalSeconds, &seconds);
+        const qreal milliseconds = round(fractional * 1000.0);
+        const QTime time(list.at(3), list.at(4), seconds, milliseconds);
         const QDateTime dt(date, time);
         if (!dt.isValid()) {
             qCWarning(KCONFIG_CORE_LOG) << errString(pKey, value, aDefault);
@@ -1044,7 +1049,7 @@ void KConfigGroup::writeEntry(const char *key, const QVariant &value,
 
             time.hour(),
             time.minute(),
-            time.second(),
+            time.second() + time.msec()/1000.0,
         };
 
         writeEntry(key, list, flags);