From 433818ca4f1384c2f4a4ec67bcadd2634e6d6c4a Mon Sep 17 00:00:00 2001
From: Klaus Basan <klaus.basan@klausbasan.de>
Date: Tue, 21 Aug 2018 22:05:39 +0200
Subject: [PATCH] Ref T308, if QDateTime is invalid (normal state) setting a
 offset turns it into a valid timestamp of 1970 (which is wrong)

---
 src/blackmisc/stringutils.cpp      | 8 ++++++--
 tests/blackmisc/testvaluecache.cpp | 5 +++--
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/blackmisc/stringutils.cpp b/src/blackmisc/stringutils.cpp
index 13ca01c2f..6413cf2ab 100644
--- a/src/blackmisc/stringutils.cpp
+++ b/src/blackmisc/stringutils.cpp
@@ -261,15 +261,19 @@ namespace BlackMisc
 
     QDateTime fromStringUtc(const QString &dateTimeString, const QString &format)
     {
+        if (dateTimeString.isEmpty() || format.isEmpty()) { return QDateTime(); }
         QDateTime dt = QDateTime::fromString(dateTimeString, format);
-        dt.setUtcOffset(0);
+        if (!dt.isValid()) { return dt; }
+        dt.setUtcOffset(0); // must only be applied to valid timestamps
         return dt;
     }
 
     QDateTime fromStringUtc(const QString &dateTimeString, Qt::DateFormat format)
     {
+        if (dateTimeString.isEmpty()) { return QDateTime(); }
         QDateTime dt = QDateTime::fromString(dateTimeString, format);
-        dt.setUtcOffset(0);
+        if (!dt.isValid()) { return dt; }
+        dt.setUtcOffset(0); // must only be applied to valid timestamps
         return dt;
     }
 
diff --git a/tests/blackmisc/testvaluecache.cpp b/tests/blackmisc/testvaluecache.cpp
index 3ce9228b6..66b4814fd 100644
--- a/tests/blackmisc/testvaluecache.cpp
+++ b/tests/blackmisc/testvaluecache.cpp
@@ -235,7 +235,7 @@ namespace BlackMiscTest
     {
         CSimulatedAircraftList aircraft({ CSimulatedAircraft("BAW001", {}, {}) });
         CAtcStationList atcStations({ CAtcStation("EGLL_TWR") });
-        CVariantMap testData
+        const CVariantMap testData
         {
             { "namespace1/value1", CVariant::from(1) },
             { "namespace1/value2", CVariant::from(2) },
@@ -260,7 +260,8 @@ namespace BlackMiscTest
         CValueCache cache2(1);
         status = cache2.loadFromFiles(dir.absolutePath());
         QVERIFY(status.isSuccess());
-        QCOMPARE(cache2.getAllValues(), testData);
+        const CVariantMap test2Values = cache2.getAllValues();
+        QCOMPARE(test2Values, testData);
     }
 
     //! Is value between 0 - 100?