QFileSystemModel/Windows: Make file name checking case-insensitive

Introduce a special hash modeled on the one used for QFileSystemWatcher
on Windows.

Task-number: QTBUG-31103
Task-number: QTBUG-64147
Change-Id: I69ebabe841716e4957ae3fb04fa5c43d233a3552
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

src/widgets/dialogs/qfilesystemmodel.cpp

@@ -1100,8 +1100,8 @@ void QFileSystemModelPrivate::sortChildren(int column, const QModelIndex &parent
         return;
 
     QVector<QFileSystemModelPrivate::QFileSystemNode*> values;
-    QHash<QString, QFileSystemNode *>::const_iterator iterator;
-    for(iterator = indexNode->children.constBegin() ; iterator != indexNode->children.constEnd() ; ++iterator) {
+
+    for (auto iterator = indexNode->children.constBegin(), cend = indexNode->children.constEnd(); iterator != cend; ++iterator) {
         if (filtersAcceptsNode(iterator.value())) {
             values.append(iterator.value());
         } else {
@@ -1661,13 +1661,10 @@ void QFileSystemModelPrivate::_q_directoryChanged(const QString &directory, cons
     QStringList toRemove;
     QStringList newFiles = files;
     std::sort(newFiles.begin(), newFiles.end());
-    QHash<QString, QFileSystemNode*>::const_iterator i = parentNode->children.constBegin();
-    while (i != parentNode->children.constEnd()) {
+    for (auto i = parentNode->children.constBegin(), cend = parentNode->children.constEnd(); i != cend; ++i) {
         QStringList::iterator iterator = std::lower_bound(newFiles.begin(), newFiles.end(), i.value()->fileName);
         if ((iterator == newFiles.end()) || (i.value()->fileName < *iterator))
             toRemove.append(i.value()->fileName);
-
-        ++i;
     }
     for (int i = 0 ; i < toRemove.count() ; ++i )
         removeNode(parentNode, toRemove[i]);

src/widgets/dialogs/qfilesystemmodel_p.h

@@ -72,6 +72,23 @@ class ExtendedInformation;
 class QFileSystemModelPrivate;
 class QFileIconProvider;
 
+#if defined(Q_OS_WIN)
+class QFileSystemModelNodePathKey : public QString
+{
+public:
+    QFileSystemModelNodePathKey() {}
+    QFileSystemModelNodePathKey(const QString &other) : QString(other) {}
+    QFileSystemModelNodePathKey(const QFileSystemModelNodePathKey &other) : QString(other) {}
+    bool operator==(const QFileSystemModelNodePathKey &other) const { return !compare(other, Qt::CaseInsensitive); }
+};
+
+Q_DECLARE_TYPEINFO(QFileSystemModelNodePathKey, Q_MOVABLE_TYPE);
+
+inline uint qHash(const QFileSystemModelNodePathKey &key) { return qHash(key.toCaseFolded()); }
+#else // Q_OS_WIN
+typedef QString QFileSystemModelNodePathKey;
+#endif
+
 class Q_AUTOTEST_EXPORT QFileSystemModelPrivate : public QAbstractItemModelPrivate
 {
     Q_DECLARE_PUBLIC(QFileSystemModel)
@@ -189,7 +206,7 @@ public:
 
         bool populatedChildren;
         bool isVisible;
-        QHash<QString,QFileSystemNode *> children;
+        QHash<QFileSystemModelNodePathKey, QFileSystemNode *> children;
         QList<QString> visibleChildren;
         int dirtyChildrenIndex;
         QFileSystemNode *parent;

tests/auto/widgets/dialogs/qfilesystemmodel/tst_qfilesystemmodel.cpp

@@ -43,6 +43,7 @@
 #if defined(Q_OS_WIN)
 # include <qt_windows.h> // for SetFileAttributes
 #endif
+#include <private/qfilesystemengine_p.h>
 
 #include <algorithm>
 
@@ -883,6 +884,18 @@ void tst_QFileSystemModel::deleteFile()
     QVERIFY(!newFile.exists());
 }
 
+static QString flipCase(QString s)
+{
+    for (int i = 0, size = s.size(); i < size; ++i) {
+        const QChar c = s.at(i);
+        if (c.isUpper())
+            s[i] = c.toLower();
+        else if (c.isLower())
+            s[i] = c.toUpper();
+    }
+    return s;
+}
+
 void tst_QFileSystemModel::caseSensitivity()
 {
     QString tmp = flatDirTestPath;
@@ -890,9 +903,23 @@ void tst_QFileSystemModel::caseSensitivity()
     files << "a" << "c" << "C";
     QVERIFY(createFiles(tmp, files));
     QModelIndex root = model->index(tmp);
+    QStringList paths;
+    QModelIndexList indexes;
     QCOMPARE(model->rowCount(root), 0);
     for (int i = 0; i < files.count(); ++i) {
-        QVERIFY(model->index(tmp + '/' + files.at(i)).isValid());
+        const QString path = tmp + '/' + files.at(i);
+        const QModelIndex index = model->index(path);
+        QVERIFY(index.isValid());
+        paths.append(path);
+        indexes.append(index);
+    }
+
+    if (!QFileSystemEngine::isCaseSensitive()) {
+        // QTBUG-31103, QTBUG-64147: Verify that files can be accessed by paths with fLipPeD case.
+        for (int i = 0; i < paths.count(); ++i) {
+            const QModelIndex flippedCaseIndex = model->index(flipCase(paths.at(i)));
+            QCOMPARE(indexes.at(i), flippedCaseIndex);
+        }
     }
 }