FTBFS with Qt 6.9.0

[tsimonq2]

libqtxdg FTBFS against the tip of qtbase upstream with the following error:

In file included from /root/libqtxdg/src/xdgiconloader/xdgiconloader.cpp:37:
/root/libqtxdg/src/xdgiconloader/xdgiconloader_p.h:64:8: error: cannot derive from ‘final’ base ‘ScalableEntry’ in derived type ‘ScalableFollowsColorEntry’
   64 | struct ScalableFollowsColorEntry : public ScalableEntry
      |        ^~~~~~~~~~~~~~~~~~~~~~~~~

This is due to https://code.qt.io/cgit/qt/qtbase.git/commit/?id=aa38df53b977d8c04123f8c0994d041d183a7971

At the top of the header file there is:

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

I'm not exactly sure how to address this.

[palinek]

Can you give a try this patch?

diff --git a/src/xdgiconloader/xdgiconloader.cpp b/src/xdgiconloader/xdgiconloader.cpp
index c299cca..2353ba4 100644
--- a/src/xdgiconloader/xdgiconloader.cpp
+++ b/src/xdgiconloader/xdgiconloader.cpp
@@ -439,7 +439,11 @@ QThemeIconInfo XdgIconLoader::findIconHelper(const QString &themeName,
                 } else if (gSupportsSvg) {
                     const QString svgPath = subDir + svgIconName;
                     if (QFile::exists(svgPath)) {
-                        std::unique_ptr<ScalableEntry> iconEntry = (followColorScheme() && theme.followsColorScheme()) ? std::make_unique<ScalableFollowsColorEntry>() : std::make_unique<ScalableEntry>();
+                        std::unique_ptr<QIconLoaderEngineEntry> iconEntry;
+                        if (followColorScheme() && theme.followsColorScheme())
+                            iconEntry = std::make_unique<ScalableFollowsColorEntry>();
+                        else
+                            iconEntry = std::make_unique<ScalableEntry>();
                         iconEntry->dir = dirInfo;
                         iconEntry->filename = svgPath;
                         info.entries.push_back(std::move(iconEntry));
diff --git a/src/xdgiconloader/xdgiconloader_p.h b/src/xdgiconloader/xdgiconloader_p.h
index 6c5f17f..cb990a9 100644
--- a/src/xdgiconloader/xdgiconloader_p.h
+++ b/src/xdgiconloader/xdgiconloader_p.h
@@ -61,13 +61,14 @@
 
 class XdgIconLoader;
 
-struct ScalableFollowsColorEntry : public ScalableEntry
+struct ScalableFollowsColorEntry : public QIconLoaderEngineEntry
 {
 #if (QT_VERSION >= QT_VERSION_CHECK(6,8,0))
     QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state, qreal scale) override;
 #else
     QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state) override;
 #endif
+    QIcon svgIcon;
 };
 
 //class QIconLoaderEngine : public QIconEngine

[tsimonq2]

@palinek Yes, that patch allows it to build. Thank you!

I will make sure the reverse dependencies build correctly with this change, but it should be good enough for a PR if you agree.

[palinek]

Created PR