use big resource variant, else we OOM on 32 bit machines

this has issues with LTO, we have a unit test that tells if stuff got lost in the DLL

fix the resource loading for static library building, uncovered by the new unit test

BUG: 487452
BUG: 499674

.gitignore

@@ -6,6 +6,7 @@
 dist
 node_modules
 /.vscode/
+/.kateproject.*
 CMakeLists.txt.user*
 .cmake/
 /.clang-format

autotests/CMakeLists.txt

@@ -1,13 +1,17 @@
 include(ECMAddTests)
 
 if(BUILD_TESTING)
-    find_package(Qt6 ${REQUIRED_QT_VERSION} CONFIG REQUIRED Core Test)
+    find_package(Qt6 ${REQUIRED_QT_VERSION} CONFIG REQUIRED Core Gui Test)
 
     configure_file(testdata.h.cmake ${CMAKE_CURRENT_BINARY_DIR}/testdata.h)
     ecm_add_test(scalabletest.cpp
         TEST_NAME "scalable"
         LINK_LIBRARIES Qt6::Test
     )
+    ecm_add_test(resourcetest.cpp
+        TEST_NAME "resource"
+        LINK_LIBRARIES KF6BreezeIcons Qt6::Gui Qt6::Test
+    )
     if(WITH_ICON_GENERATION)
         add_test(NAME "test24x24icons" COMMAND ${Python_EXECUTABLE} ${CMAKE_SOURCE_DIR}/autotests/test24x24icons.py
             WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}

autotests/resourcetest.cpp

@@ -0,0 +1,68 @@
+/*
+    This file is part of the KDE libraries
+
+    SPDX-FileCopyrightText: 2025 Christoph Cullmann <cullmann@kde.org>
+
+    SPDX-License-Identifier: LGPL-2.0-or-later
+*/
+
+#include <QFile>
+#include <QObject>
+#include <QTest>
+
+#include "breezeicons.h"
+#include "testhelpers.h"
+
+class ResourceTest : public QObject
+{
+    Q_OBJECT
+
+    void compareFileResourceWithFilesystem(const QString &name)
+    {
+        // resource location
+        const QString qrcLocation(QStringLiteral(":/icons/breeze/%1").arg(name));
+
+        // file system location
+        const QString fsLocation(PROJECT_SOURCE_DIR + QStringLiteral("/icons/%1").arg(name));
+
+        // read full data of both, must work
+        QFile qrcFile(qrcLocation);
+        QVERIFY(qrcFile.open(QFile::ReadOnly));
+        QFile fsFile(fsLocation);
+        QVERIFY(fsFile.open(QFile::ReadOnly));
+        const auto qrcData = qrcFile.readAll();
+        QVERIFY(!qrcData.isEmpty());
+        const auto fsData = fsFile.readAll();
+        QVERIFY(!fsData.isEmpty());
+
+        // fully equal?
+        QCOMPARE(qrcData, fsData);
+    }
+
+private Q_SLOTS:
+    // check that not stuff got lost in the DLL
+    // did happen for compiling with LTO or buggy preprocessing the DLL
+    void test_resourceContainsTheme()
+    {
+        // ensure the DLL is linked
+        BreezeIcons::initIcons();
+
+        // we want to have the proper theme file
+        compareFileResourceWithFilesystem(QStringLiteral("index.theme"));
+
+        // check some icons we know shall be there
+        // check no stuff that might not be generated in some config or that is a symlink
+        compareFileResourceWithFilesystem(QStringLiteral("actions/16/go-previous.svg"));
+        compareFileResourceWithFilesystem(QStringLiteral("actions/16/table.svg"));
+        compareFileResourceWithFilesystem(QStringLiteral("actions/22/edit-paste.svg"));
+        compareFileResourceWithFilesystem(QStringLiteral("actions/22/tab-new.svg"));
+        compareFileResourceWithFilesystem(QStringLiteral("actions/32/document-edit.svg"));
+        compareFileResourceWithFilesystem(QStringLiteral("actions/32/zoom.svg"));
+        compareFileResourceWithFilesystem(QStringLiteral("mimetypes/64/application-json.svg"));
+        compareFileResourceWithFilesystem(QStringLiteral("places/64/folder-favorites.svg"));
+    }
+};
+
+QTEST_GUILESS_MAIN(ResourceTest)
+
+#include "resourcetest.moc"

src/lib/CMakeLists.txt

@@ -24,8 +24,9 @@ if(BINARY_ICONS_RESOURCE)
     install(FILES ${RESOURCE_FILE_BINARY} DESTINATION ${KDE_INSTALL_FULL_ICONDIR}/breeze)
 endif()
 
-# use normal resource adding, big resource variant has issue with LTO
-qt_add_resources(kbreezeicons_resource_SRCS
+# use big resource variant, else we OOM on 32 bit machines
+# this has issues with LTO, we have a unit test that tells if stuff got lost in the DLL
+qt_add_big_resources(kbreezeicons_resource_SRCS
     ${RESOURCE_FILE}
     OPTIONS --root /icons/breeze
 )

src/lib/breezeicons.cpp

@@ -10,11 +10,20 @@
 
 #include <QIcon>
 
+static void resourceInit()
+{
+    // needs to be called outside of namespace
+    Q_INIT_RESOURCE(breeze_icons);
+}
+
 namespace BreezeIcons
 {
 
 void initIcons()
 {
+    // ensure the resource is there and loaded for static libs
+    resourceInit();
+
     // ensure we fallback to breeze, if no user fallback is set
     const QString fallbackTheme = QIcon::fallbackThemeName();
     if (fallbackTheme.isEmpty() || fallbackTheme == QLatin1String("hicolor")) {