[Theme] Carry Default theme directory customizations over to System (#7385)

* [Theme] Carry Default theme directory customizations over to System

The Default -> System rename rewrote the stored theme name but left the
user profile's themes/Default directory behind, so anyone who had
customized zone graphics, stylesheets or palettes there silently lost them.

Migrate the directory alongside the name. Rename it when System does not
exist yet, otherwise merge file by file without overwriting what System
already has, then drop the legacy directory. Users who already ran the
rename get their customizations back on the next start, and a hand-made
Default folder of a user on another theme is left untouched.

* [Tests] Give theme_migration_test an explicit main and gate it on WITH_CLIENT

The build machines that cannot find GTest fall back to the downloaded
googletest, which links the bare gtest library without gtest_main. Every
other test defines its own main() for that reason; this one did not, so
Debian 13, Fedora 44 and Ubuntu 26.04 failed to link it.

The test compiles client sources, so -DTEST=1 -DWITH_CLIENT=0 has no way
to build it. Gate the subdirectory on WITH_CLIENT like the other
client-source test.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

tests/CMakeLists.txt

@@ -178,6 +178,11 @@ add_subdirectory(movecard_tests)
 add_subdirectory(oracle)
 add_subdirectory(settings)
 
+# theme_migration_test compiles client sources, whose headers are only reachable from a client build.
+if(WITH_CLIENT)
+  add_subdirectory(theme_migration)
+endif()
+
 # picture_loader_benchmark links libcockatrice_settings, which only exists when
 # a client/UI-capable target is being built.
 if(WITH_ORACLE OR WITH_CLIENT)

tests/settings/settings_migration_test.cpp

@@ -542,6 +542,34 @@ TEST_F(SettingsMigrationTest, PartialMigrationOnlyMigratesPresentKeys)
     ASSERT_FALSE(fileExists("chat.ini"));
 }
 
+TEST_F(SettingsMigrationTest, ThemeNameDefaultIsRewrittenToSystem)
+{
+    {
+        QSettings g(settingsPath + "global.ini", QSettings::IniFormat);
+        g.setValue("theme/name", "Default");
+        g.sync();
+    }
+
+    ASSERT_TRUE(SettingsMigration::migrateSettingsFromGlobalIni(settingsPath));
+
+    ASSERT_TRUE(fileExists("appearance.ini"));
+    ASSERT_EQ(readFromIni("appearance.ini", "appearance/themeName"), QVariant("System"));
+}
+
+TEST_F(SettingsMigrationTest, OtherThemeNamesAreLeftAlone)
+{
+    {
+        QSettings g(settingsPath + "global.ini", QSettings::IniFormat);
+        g.setValue("theme/name", "VelvetMarble");
+        g.sync();
+    }
+
+    ASSERT_TRUE(SettingsMigration::migrateSettingsFromGlobalIni(settingsPath));
+
+    ASSERT_TRUE(fileExists("appearance.ini"));
+    ASSERT_EQ(readFromIni("appearance.ini", "appearance/themeName"), QVariant("VelvetMarble"));
+}
+
 TEST_F(SettingsMigrationTest, KeyMapTranslationIsCorrect)
 {
     {

tests/theme_migration/CMakeLists.txt

@@ -0,0 +1,30 @@
+add_executable(
+  theme_migration_test
+  ${CMAKE_SOURCE_DIR}/cockatrice/src/interface/theme_manager.cpp
+  ${CMAKE_SOURCE_DIR}/cockatrice/src/interface/theme_config.cpp
+  ${CMAKE_SOURCE_DIR}/cockatrice/src/interface/pixel_map_generator.cpp
+  ${CMAKE_SOURCE_DIR}/cockatrice/src/client/settings/cache_settings.cpp
+  ${CMAKE_SOURCE_DIR}/cockatrice/src/client/settings/card_counter_settings.cpp
+  ${CMAKE_SOURCE_DIR}/cockatrice/src/client/settings/shortcuts_settings.cpp
+  ${CMAKE_SOURCE_DIR}/cockatrice/src/client/network/update/client/release_channel.cpp
+  ${VERSION_STRING_CPP}
+  theme_migration_test.cpp
+)
+target_include_directories(theme_migration_test PRIVATE ${CMAKE_SOURCE_DIR}/cockatrice/src)
+
+target_link_libraries(
+  theme_migration_test
+  libcockatrice_settings
+  libcockatrice_network
+  libcockatrice_network_server_remote
+  libcockatrice_protocol
+  Threads::Threads
+  ${GTEST_BOTH_LIBRARIES}
+  ${TEST_QT_MODULES}
+)
+
+add_test(NAME theme_migration_test COMMAND theme_migration_test)
+
+if(NOT GTEST_FOUND)
+  add_dependencies(theme_migration_test gtest)
+endif()

tests/theme_migration/theme_migration_test.cpp

@@ -0,0 +1,154 @@
+#include "interface/theme_manager.h"
+
+#include <QDir>
+#include <QFile>
+#include <QFileInfo>
+#include <QString>
+#include <QTemporaryDir>
+#include <gtest/gtest.h>
+
+// Owned by main.cpp in the real application; pixel_map_generator.cpp references
+// it, so the test binary needs a definition even though it never renders.
+ThemeManager *themeManager = nullptr;
+
+namespace
+{
+const QString LEGACY = QStringLiteral("Default");
+const QString CURRENT = QStringLiteral("System");
+
+// Writes content at <themesPath>/<theme>/<relativePath>, creating parents.
+void writeThemeFile(const QString &themesPath,
+                    const QString &theme,
+                    const QString &relativePath,
+                    const QByteArray &content)
+{
+    const QString filePath = QDir(QDir(themesPath).absoluteFilePath(theme)).absoluteFilePath(relativePath);
+    ASSERT_TRUE(QDir().mkpath(QFileInfo(filePath).absolutePath()));
+    QFile file(filePath);
+    ASSERT_TRUE(file.open(QIODevice::WriteOnly));
+    file.write(content);
+    file.close();
+}
+
+QByteArray readThemeFile(const QString &themesPath, const QString &theme, const QString &relativePath)
+{
+    QFile file(QDir(QDir(themesPath).absoluteFilePath(theme)).absoluteFilePath(relativePath));
+    if (!file.open(QIODevice::ReadOnly)) {
+        return QByteArray();
+    }
+    return file.readAll();
+}
+
+class ThemeMigrationTest : public ::testing::Test
+{
+protected:
+    QTemporaryDir tmp;
+    QString themesPath;
+
+    void SetUp() override
+    {
+        ASSERT_TRUE(tmp.isValid());
+        themesPath = QDir(tmp.path()).absoluteFilePath("themes");
+        ASSERT_TRUE(QDir().mkpath(themesPath));
+    }
+};
+
+} // namespace
+
+TEST_F(ThemeMigrationTest, NoLegacyDirectoryIsANoOp)
+{
+    writeThemeFile(themesPath, CURRENT, "theme.cfg", "[Appearance]\n");
+
+    ThemeManager::migrateLegacyThemeDir(themesPath, CURRENT);
+
+    EXPECT_TRUE(QDir(QDir(themesPath).absoluteFilePath(CURRENT)).exists());
+    EXPECT_TRUE(QDir(QDir(themesPath).absoluteFilePath(LEGACY)).exists() == false);
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "theme.cfg").toStdString(), std::string("[Appearance]\n"));
+}
+
+TEST_F(ThemeMigrationTest, RenamesDirectoryWhenTargetIsFree)
+{
+    // A customised "Default": stylesheet, zone graphics in a subdirectory and a
+    // palette, i.e. everything a user is liable to have personalised.
+    writeThemeFile(themesPath, LEGACY, "style.css", "QPushButton { color: red; }");
+    writeThemeFile(themesPath, LEGACY, "zones/handzone.png", "handzone-bytes");
+    writeThemeFile(themesPath, LEGACY, "zones/tablezone-dark.svg", "tablezone-bytes");
+    writeThemeFile(themesPath, LEGACY, "palette-dark.toml", "palette");
+
+    ThemeManager::migrateLegacyThemeDir(themesPath, LEGACY);
+
+    EXPECT_FALSE(QDir(QDir(themesPath).absoluteFilePath(LEGACY)).exists());
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "style.css").toStdString(),
+              std::string("QPushButton { color: red; }"));
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "zones/handzone.png").toStdString(), std::string("handzone-bytes"));
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "zones/tablezone-dark.svg").toStdString(),
+              std::string("tablezone-bytes"));
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "palette-dark.toml").toStdString(), std::string("palette"));
+}
+
+TEST_F(ThemeMigrationTest, RenamesForAnAlreadyMigratedUserWhoseDirectoryWasLeftBehind)
+{
+    // The settings value was rewritten to "System" on an earlier run, but the
+    // customised directory is still called "Default". The customisations are
+    // still reachable and must still be carried over.
+    writeThemeFile(themesPath, LEGACY, "style.css", "legacy-css");
+
+    ThemeManager::migrateLegacyThemeDir(themesPath, CURRENT);
+
+    EXPECT_FALSE(QDir(QDir(themesPath).absoluteFilePath(LEGACY)).exists());
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "style.css").toStdString(), std::string("legacy-css"));
+}
+
+TEST_F(ThemeMigrationTest, MergesIntoAnExistingTargetWithoutOverwriting)
+{
+    // Post-rename re-customisation: "System" already exists and holds newer
+    // files. Those win; the legacy directory only fills the gaps.
+    writeThemeFile(themesPath, CURRENT, "style.css", "newer-css");
+    writeThemeFile(themesPath, CURRENT, "zones/handzone.png", "newer-handzone");
+    writeThemeFile(themesPath, LEGACY, "style.css", "legacy-css");
+    writeThemeFile(themesPath, LEGACY, "zones/handzone.png", "legacy-handzone");
+    writeThemeFile(themesPath, LEGACY, "zones/stackzone.png", "legacy-stackzone");
+    writeThemeFile(themesPath, LEGACY, "palette-light.toml", "legacy-palette");
+
+    ThemeManager::migrateLegacyThemeDir(themesPath, CURRENT);
+
+    EXPECT_FALSE(QDir(QDir(themesPath).absoluteFilePath(LEGACY)).exists());
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "style.css").toStdString(), std::string("newer-css"));
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "zones/handzone.png").toStdString(), std::string("newer-handzone"));
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "zones/stackzone.png").toStdString(), std::string("legacy-stackzone"));
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "palette-light.toml").toStdString(), std::string("legacy-palette"));
+}
+
+TEST_F(ThemeMigrationTest, LeavesAnotherThemesDefaultDirectoryAlone)
+{
+    // A user on an unrelated theme may legitimately have made a "Default"
+    // folder of their own; it must not be folded into "System".
+    writeThemeFile(themesPath, LEGACY, "style.css", "unrelated");
+
+    ThemeManager::migrateLegacyThemeDir(themesPath, QStringLiteral("Leather"));
+
+    EXPECT_TRUE(QDir(QDir(themesPath).absoluteFilePath(LEGACY)).exists());
+    EXPECT_EQ(readThemeFile(themesPath, LEGACY, "style.css").toStdString(), std::string("unrelated"));
+    EXPECT_FALSE(QDir(QDir(themesPath).absoluteFilePath(CURRENT)).exists());
+}
+
+TEST_F(ThemeMigrationTest, IsIdempotent)
+{
+    writeThemeFile(themesPath, LEGACY, "style.css", "css");
+
+    ThemeManager::migrateLegacyThemeDir(themesPath, LEGACY);
+    ASSERT_EQ(readThemeFile(themesPath, CURRENT, "style.css").toStdString(), std::string("css"));
+
+    ThemeManager::migrateLegacyThemeDir(themesPath, CURRENT);
+    ThemeManager::migrateLegacyThemeDir(themesPath, LEGACY);
+
+    EXPECT_EQ(readThemeFile(themesPath, CURRENT, "style.css").toStdString(), std::string("css"));
+}
+
+// Every test brings its own main(): GTest is not guaranteed to be found on the build machines, and
+// the fallback then links the bare gtest library without gtest_main.
+int main(int argc, char **argv)
+{
+    ::testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}