Don't rely on uninitialized data

When we fail to get file attributes, the file times are left in an
uninitialized state, which may lead to a crash. In particular, this was
showing up in QMessageBox's autotest, where the lastModified time is
being queried on a non-existing file.

Before the refactoring, we were returning a default constructed
QDateTime to queries about different file times, with this change we
will return the time corresponding to a default constructed FILETIME
object.

Reviewed-by: Shane Kearns

1 files changed, 45 insertions, 0 deletions

diff --git a/tests/auto/qfileinfo/tst_qfileinfo.cpp b/tests/auto/qfileinfo/tst_qfileinfo.cpp
index 0a61d55..4d9e80b 100644
--- a/tests/auto/qfileinfo/tst_qfileinfo.cpp
+++ b/tests/auto/qfileinfo/tst_qfileinfo.cpp
@@ -196,6 +196,8 @@ private slots:
     void owner();
 #endif
     void group();
+
+    void invalidState();
 };
 
 tst_QFileInfo::tst_QFileInfo()
@@ -1761,5 +1763,48 @@ void tst_QFileInfo::group()
     QCOMPARE(fi.group(), expected);
 }
 
+void tst_QFileInfo::invalidState()
+{
+    // Shouldn't crash;
+
+    {
+        QFileInfo info;
+        QCOMPARE(info.size(), qint64(0));
+        QVERIFY(!info.exists());
+
+        info.setCaching(false);
+
+        info.created();
+        info.lastRead();
+        info.lastModified();
+    }
+
+    {
+        QFileInfo info("");
+        QCOMPARE(info.size(), qint64(0));
+        QVERIFY(!info.exists());
+
+        info.setCaching(false);
+
+        info.created();
+        info.lastRead();
+        info.lastModified();
+    }
+
+    {
+        QFileInfo info("file-doesn't-really-exist.txt");
+        QCOMPARE(info.size(), qint64(0));
+        QVERIFY(!info.exists());
+
+        info.setCaching(false);
+
+        info.created();
+        info.lastRead();
+        info.lastModified();
+    }
+
+    QVERIFY(true);
+}
+
 QTEST_MAIN(tst_QFileInfo)
 #include "tst_qfileinfo.moc"