Strip any trailing spaces from the filename before trying to open it

On Windows, trailing spaces in a filename are silently ignored, so we
need to strip it before trying to open a file with it. Otherwise it ends
up being stripped later and in a case like " ." it will end up causing
Qt to think that a folder exists when it does not.

[ChangeLog][Platform Specific Changes][Windows][QtWidgets][QFileDialog]
Handled the case of having trailing spaces in a filename correctly so if
the filename ends up being empty that the parent path is used instead.

Change-Id: I6500cc3a44746bf4a65e73bcfb63265a0a97c8a3
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

src/widgets/dialogs/qfilesystemmodel.cpp

@@ -401,9 +401,18 @@ QFileSystemModelPrivate::QFileSystemNode *QFileSystemModelPrivate::node(const QS
     for (int i = 0; i < pathElements.count(); ++i) {
         QString element = pathElements.at(i);
 #ifdef Q_OS_WIN
-        // On Windows, "filename......." and "filename" are equivalent Task #133928
+        // On Windows, "filename    " and "filename" are equivalent and
-        while (element.endsWith(QLatin1Char('.')))
+        // "filename  .  " and "filename" are equivalent
+        // "filename......." and "filename" are equivalent Task #133928
+        // whereas "filename  .txt" is still "filename  .txt"
+        // If after stripping the characters there is nothing left then we
+        // just return the parent directory as it is assumed that the path
+        // is referring to the parent
+        while (element.endsWith(QLatin1Char('.')) || element.endsWith(QLatin1Char(' ')))
             element.chop(1);
+        // Only filenames that can't possibly exist will be end up being empty
+        if (element.isEmpty())
+            return parent;
 #endif
         bool alreadyExisted = parent->children.contains(element);
 

tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp

@@ -148,6 +148,7 @@ private slots:
     void enableChooseButton();
     void hooks();
     void widgetlessNativeDialog();
+    void trailingDotsAndSpaces();
 #ifdef Q_OS_UNIX
 #ifdef QT_BUILD_INTERNAL
     void tildeExpansion_data();
@@ -1413,6 +1414,33 @@ void tst_QFiledialog::widgetlessNativeDialog()
     QVERIFY(!button);
 }
 
+void tst_QFiledialog::trailingDotsAndSpaces()
+{
+#ifndef Q_OS_WIN
+    QSKIP("This is only tested on Windows");
+#endif
+    QNonNativeFileDialog fd;
+    fd.setViewMode(QFileDialog::List);
+    fd.setFileMode(QFileDialog::ExistingFile);
+    fd.setOptions(QFileDialog::DontUseNativeDialog);
+    fd.show();
+    QLineEdit *lineEdit = fd.findChild<QLineEdit *>("fileNameEdit");
+    QVERIFY(lineEdit);
+    QListView *list = fd.findChild<QListView *>("listView");
+    QVERIFY(list);
+    QTest::qWait(1000);
+    int currentChildrenCount = list->model()->rowCount(list->rootIndex());
+    QTest::keyClick(lineEdit, Qt::Key_Space);
+    QTest::keyClick(lineEdit, Qt::Key_Period);
+    QTest::qWait(1000);
+    QVERIFY(currentChildrenCount == list->model()->rowCount(list->rootIndex()));
+    lineEdit->clear();
+    QTest::keyClick(lineEdit, Qt::Key_Period);
+    QTest::keyClick(lineEdit, Qt::Key_Space);
+    QTest::qWait(1000);
+    QVERIFY(currentChildrenCount == list->model()->rowCount(list->rootIndex()));
+}
+
 #ifdef Q_OS_UNIX
 #ifdef QT_BUILD_INTERNAL
 void tst_QFiledialog::tildeExpansion_data()