Make QFile::open fail when using an invalid file name

Fixes the bug in QFile which allowed opening a file with reserved
characters in its name.  If the name is a long file path, CreateFile
opens a file with a truncated name instead of failing, so we have
to catch reserved characters ourselves.

[ChangeLog][Windows] Fixed a bug that caused QFile to create
files with truncated names if the file name was invalid. Now,
QFile::open correctly fails to create such files.

Task-number: QTBUG-57023
Change-Id: I01d5a7132054cecdfa839d0b8de06460039248a3
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

2 files changed, 15 insertions, 0 deletions

diff --git a/src/corelib/io/qfsfileengine_win.cpp b/src/corelib/io/qfsfileengine_win.cpp
index ab651ead79..7d16e59195 100644
--- a/src/corelib/io/qfsfileengine_win.cpp
+++ b/src/corelib/io/qfsfileengine_win.cpp
@@ -108,6 +108,20 @@ bool QFSFileEnginePrivate::nativeOpen(QIODevice::OpenMode openMode)
 {
     Q_Q(QFSFileEngine);
 
+    // Check if the file name is valid:
+    // https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx#naming_conventions
+    const QString fileName = fileEntry.fileName();
+    for (QString::const_iterator it = fileName.constBegin(), end = fileName.constEnd();
+         it != end; ++it) {
+        const QChar c = *it;
+        if (c == QLatin1Char('<') || c == QLatin1Char('>') || c == QLatin1Char(':') ||
+            c == QLatin1Char('\"') || c == QLatin1Char('/') || c == QLatin1Char('\\') ||
+            c == QLatin1Char('|') || c == QLatin1Char('?') || c == QLatin1Char('*')) {
+            q->setError(QFile::OpenError, QStringLiteral("Invalid file name"));
+            return false;
+        }
+    }
+
     // All files are opened in share mode (both read and write).
     DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
 
diff --git a/tests/auto/corelib/io/qfile/tst_qfile.cpp b/tests/auto/corelib/io/qfile/tst_qfile.cpp
index a6da6d8e69..a23ebc8d72 100644
--- a/tests/auto/corelib/io/qfile/tst_qfile.cpp
+++ b/tests/auto/corelib/io/qfile/tst_qfile.cpp
@@ -1141,6 +1141,7 @@ void tst_QFile::invalidFile_data()
 #else
 #if !defined(Q_OS_WINRT)
     QTest::newRow( "colon2" ) << invalidDriveLetter() + QString::fromLatin1(":ail:invalid");
+    QTest::newRow( "date" ) << QString( "testLog-03:20.803Z.txt" );
 #endif
     QTest::newRow( "colon3" ) << QString( ":failinvalid" );
     QTest::newRow( "forwardslash" ) << QString( "fail/invalid" );