Address Qt 5 to-do comments related to QFileSystemModel.

- QFileSystemModel::rmdir() and QFileSystemModel::remove() changed to
  non-const -- they don't change the object, but they do change the
  file system, and the Qt way is to be non-const if having side-effects
  on external entities.
- The comment on incompatibility between entryList and QFileInfo will
  not be fixed as doing so is likely to break existing code.
- The comment on removing the internal resolvedSymLinks variable has
  been removed, as the variable is still used.

Task-number: QTBUG-25088
Change-Id: I20456e4d116076403d9c4d4692ee05c178a1ed17
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

src/widgets/dialogs/qfilesystemmodel.cpp

@@ -129,7 +129,7 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \fn bool QFileSystemModel::rmdir(const QModelIndex &index) const
+    \fn bool QFileSystemModel::rmdir(const QModelIndex &index)
 
     Removes the directory corresponding to the model item \a index in the
     file system model and \b{deletes the corresponding directory from the
@@ -185,7 +185,7 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
-    \fn bool QFileSystemModel::remove(const QModelIndex &index) const
+    \fn bool QFileSystemModel::remove(const QModelIndex &index)
 
     Removes the model item \a index from the file system model and \b{deletes the
     corresponding file from the file system}, returning true if successful. If the
@@ -197,7 +197,7 @@ QT_BEGIN_NAMESPACE
     \sa rmdir()
 */
 
-bool QFileSystemModel::remove(const QModelIndex &aindex) const
+bool QFileSystemModel::remove(const QModelIndex &aindex)
 {
     //### TODO optim
     QString path = filePath(aindex);
@@ -1653,7 +1653,7 @@ bool QFileSystemModel::event(QEvent *event)
     return QAbstractItemModel::event(event);
 }
 
-bool QFileSystemModel::rmdir(const QModelIndex &aindex) const
+bool QFileSystemModel::rmdir(const QModelIndex &aindex)
 {
     QString path = filePath(aindex);
     QFileSystemModelPrivate * d = const_cast<QFileSystemModelPrivate*>(d_func());
@@ -1985,8 +1985,7 @@ bool QFileSystemModelPrivate::filtersAcceptsNode(const QFileSystemNode *node) co
     const bool hideDot           = (filters & QDir::NoDot);
     const bool hideDotDot        = (filters & QDir::NoDotDot);
 
-    // Note that we match the behavior of entryList and not QFileInfo on this and this
-    // incompatibility won't be fixed until Qt 5 at least
+    // Note that we match the behavior of entryList and not QFileInfo on this.
     bool isDot    = (node->fileName == QLatin1String("."));
     bool isDotDot = (node->fileName == QLatin1String(".."));
     if (   (hideHidden && !(isDot || isDotDot) && node->isHidden())

src/widgets/dialogs/qfilesystemmodel.h

@@ -138,12 +138,12 @@ public:
     QDateTime lastModified(const QModelIndex &index) const;
 
     QModelIndex mkdir(const QModelIndex &parent, const QString &name);
-    bool rmdir(const QModelIndex &index) const; // ### Qt5: should not be const
+    bool rmdir(const QModelIndex &index);
     inline QString fileName(const QModelIndex &index) const;
     inline QIcon fileIcon(const QModelIndex &index) const;
     QFile::Permissions permissions(const QModelIndex &index) const;
     inline QFileInfo fileInfo(const QModelIndex &index) const;
-    bool remove(const QModelIndex &index) const;
+    bool remove(const QModelIndex &index);
 
 protected:
     QFileSystemModel(QFileSystemModelPrivate &, QObject *parent = 0);

src/widgets/dialogs/qfilesystemmodel_p.h

@@ -315,7 +315,6 @@ public:
 #ifndef QT_NO_REGEXP
     QList<QRegExp> nameFilters;
 #endif
-    // ### Qt 5: resolvedSymLinks goes away
     QHash<QString, QString> resolvedSymLinks;
 
     QFileSystemNode root;