Reset QTemporaryFile's state after failed open() on Windows

This fixes a regression introduced in 4.5.2 where QTemporaryFile would
no longer attempt to generate a random name after a failed open. Under
certain situations, this led to a non-random file being left behind in
QDir::tempPath when using the fallback implementation of QFile::copy.

Avoid calling QFSFileEngine::setFileName() on a template, so as not to
process it as file name.

By consistently not calling setFileTemplate in the constructor, we also
delay allocation of the fileEngine. Changes made to that function also
keep it from unnecessarily allocating the fileEngine.

Task-number: 260165
Reviewed-by: Thiago Macieira

1 files changed, 82 insertions, 0 deletions

diff --git a/tests/auto/qtemporaryfile/tst_qtemporaryfile.cpp b/tests/auto/qtemporaryfile/tst_qtemporaryfile.cpp
index 2541b48d88..73486e709b 100644
--- a/tests/auto/qtemporaryfile/tst_qtemporaryfile.cpp
+++ b/tests/auto/qtemporaryfile/tst_qtemporaryfile.cpp
@@ -89,6 +89,8 @@ private slots:
     void renameFdLeak();
     void reOpenThroughQFile();
     void keepOpenMode();
+    void resetTemplateAfterError();
+    void setTemplateAfterOpen();
 
 public:
 };
@@ -472,5 +474,85 @@ void tst_QTemporaryFile::keepOpenMode()
     }
 }
 
+void tst_QTemporaryFile::resetTemplateAfterError()
+{
+    // calling setFileTemplate on a failed open
+
+    QString tempPath = QDir::tempPath();
+
+    QString const fileTemplate("destination/qt_temp_file_test.XXXXXX");
+    QString const fileTemplate2(tempPath + "/qt_temp_file_test.XXXXXX");
+
+    QVERIFY2( QDir(tempPath).exists() || QDir().mkpath(tempPath), "Test precondition" );
+    QVERIFY2( !QFile::exists("destination"), "Test precondition" );
+    QVERIFY2( !QFile::exists(fileTemplate2) || QFile::remove(fileTemplate2), "Test precondition" );
+
+    QFile file(fileTemplate2);
+    QByteArray fileContent("This file is intentionally NOT left empty.");
+
+    QVERIFY( file.open(QIODevice::ReadWrite | QIODevice::Truncate) );
+    QCOMPARE( file.write(fileContent), (qint64)fileContent.size() );
+    QVERIFY( file.flush() );
+
+    QString fileName;
+    {
+        QTemporaryFile temp;
+
+        QVERIFY( temp.fileName().isEmpty() );
+        QVERIFY( !temp.fileTemplate().isEmpty() );
+
+        temp.setFileTemplate( fileTemplate );
+
+        QVERIFY( temp.fileName().isEmpty() );
+        QCOMPARE( temp.fileTemplate(), fileTemplate );
+
+        QVERIFY( !temp.open() );
+
+        QVERIFY( temp.fileName().isEmpty() );
+        QCOMPARE( temp.fileTemplate(), fileTemplate );
+
+        temp.setFileTemplate( fileTemplate2 );
+        QVERIFY( temp.open() );
+
+        fileName = temp.fileName();
+        QVERIFY( QFile::exists(fileName) );
+        QVERIFY( !fileName.isEmpty() );
+        QVERIFY2( fileName != fileTemplate2,
+            ("Generated name shouldn't be same as template: " + fileTemplate2).toLocal8Bit().constData() );
+    }
+
+    QVERIFY( !QFile::exists(fileName) );
+
+    file.seek(0);
+    QCOMPARE( QString(file.readAll()), QString(fileContent) );
+    QVERIFY( file.remove() );
+}
+
+void tst_QTemporaryFile::setTemplateAfterOpen()
+{
+    QTemporaryFile temp;
+
+    QVERIFY( temp.fileName().isEmpty() );
+    QVERIFY( !temp.fileTemplate().isEmpty() );
+
+    QVERIFY( temp.open() );
+
+    QString const fileName = temp.fileName();
+    QString const newTemplate("funny-path/funny-name-XXXXXX.tmp");
+
+    QVERIFY( !fileName.isEmpty() );
+    QVERIFY( QFile::exists(fileName) );
+    QVERIFY( !temp.fileTemplate().isEmpty() );
+    QVERIFY( temp.fileTemplate() != newTemplate );
+
+    temp.close(); // QTemporaryFile::setFileTemplate will assert on isOpen() up to 4.5.2
+    temp.setFileTemplate(newTemplate);
+    QCOMPARE( temp.fileTemplate(), newTemplate );
+
+    QVERIFY( temp.open() );
+    QCOMPARE( temp.fileName(), fileName );
+    QCOMPARE( temp.fileTemplate(), newTemplate );
+}
+
 QTEST_MAIN(tst_QTemporaryFile)
 #include "tst_qtemporaryfile.moc"