[qt] fix various crashes due to invalid/corrupted/outdated settings (#4070)

lots of "out of index" errors :)

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4070
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

13 files changed, 149 insertions, 71 deletions

diff --git a/src/common/settings.h b/src/common/settings.h
index 3e14a40a09..be9c080bc6 100644
--- a/src/common/settings.h
+++ b/src/common/settings.h
@@ -336,7 +336,7 @@ struct Values {
         RendererBackend::Vulkan,
 #endif
         "backend", Category::Renderer};
-    SwitchableSetting<int> vulkan_device{linkage, 0, "vulkan_device", Category::Renderer, Specialization::RuntimeList};
+    SwitchableSetting<u32> vulkan_device{linkage, 0, "vulkan_device", Category::Renderer, Specialization::RuntimeList};
 
     // Graphics Settings
     ResolutionScalingInfo resolution_info{};
@@ -661,8 +661,8 @@ struct Values {
                                       false,   true, &custom_rtc_enabled};
     SwitchableSetting<s64, true> custom_rtc_offset{linkage,
                                                    0,
-                                                   (std::numeric_limits<int>::min)(),
-                                                   (std::numeric_limits<int>::max)(),
+                                                   (std::numeric_limits<s64>::min)(),
+                                                   (std::numeric_limits<s64>::max)(),
                                                    "custom_rtc_offset",
                                                    Category::System,
                                                    Specialization::Countable,
@@ -751,7 +751,7 @@ struct Values {
 
     Setting<std::string> touch_device{linkage, "min_x:100,min_y:50,max_x:1800,max_y:850",
                                       "touch_device", Category::Controls};
-    Setting<int> touch_from_button_map_index{linkage, 0, "touch_from_button_map",
+    Setting<u32> touch_from_button_map_index{linkage, 0, "touch_from_button_map",
                                              Category::Controls};
     std::vector<TouchFromButtonMap> touch_from_button_maps;
 
diff --git a/src/common/settings_enums.h b/src/common/settings_enums.h
index da142e8e1c..a71cf2141c 100644
--- a/src/common/settings_enums.h
+++ b/src/common/settings_enums.h
@@ -145,8 +145,8 @@ ENUM(ConfirmStop, Ask_Always, Ask_Based_On_Game, Ask_Never);
 ENUM(FullscreenMode, Borderless, Exclusive);
 ENUM(NvdecEmulation, Off, Cpu, Gpu);
 ENUM(ResolutionSetup, Res1_4X, Res1_2X, Res3_4X, Res1X, Res5_4X, Res3_2X, Res2X, Res3X, Res4X, Res5X, Res6X, Res7X, Res8X);
-ENUM(ScalingFilter, NearestNeighbor, Bilinear, Bicubic, Gaussian, Lanczos, ScaleForce, Fsr, Area, ZeroTangent, BSpline, Mitchell, Spline1, Mmpx, Sgsr, SgsrEdge, MaxEnum);
-ENUM(AntiAliasing, None, Fxaa, Smaa, MaxEnum);
+ENUM(ScalingFilter, NearestNeighbor, Bilinear, Bicubic, Gaussian, Lanczos, ScaleForce, Fsr, Area, ZeroTangent, BSpline, Mitchell, Spline1, Mmpx, Sgsr, SgsrEdge);
+ENUM(AntiAliasing, None, Fxaa, Smaa);
 ENUM(AspectRatio, R16_9, R4_3, R21_9, R16_10, Stretch);
 ENUM(ConsoleMode, Handheld, Docked);
 ENUM(AppletMode, HLE, LLE);
diff --git a/src/common/settings_setting.h b/src/common/settings_setting.h
index 076aceef29..9b6ec76d62 100644
--- a/src/common/settings_setting.h
+++ b/src/common/settings_setting.h
@@ -11,6 +11,7 @@
 #include <optional>
 #include <stdexcept>
 #include <string>
+#include <type_traits>
 #include <typeindex>
 #include <typeinfo>
 #include <fmt/core.h>
@@ -101,7 +102,15 @@ public:
      * @param val The desired value
      */
     virtual void SetValue(const Type& val) {
-        Type temp{ranged ? std::clamp(val, minimum, maximum) : val};
+        // Enums have a maximal range which they're allowed
+        Type temp{};
+        if constexpr (std::is_enum_v<Type>) {
+            auto const r_min = std::underlying_type_t<Type>(0);
+            auto const r_max = std::underlying_type_t<Type>(EnumMetadata<Type>::GetLast());
+            temp = Type(std::clamp(std::underlying_type_t<Type>(val), r_min, r_max));
+        } else {
+            temp = ranged ? std::clamp(val, this->minimum, this->maximum) : val;
+        }
         std::swap(value, temp);
     }
 
@@ -129,7 +138,7 @@ protected:
         } else if constexpr (std::is_floating_point_v<Type>) {
             return fmt::format("{:f}", value_);
         } else if constexpr (std::is_enum_v<Type>) {
-            return std::to_string(u32(value_));
+            return std::to_string(std::underlying_type_t<Type>(value_));
         } else {
             return std::to_string(value_);
         }
@@ -371,7 +380,15 @@ public:
      * @param val The new value
      */
     void SetValue(const Type& val) override final {
-        Type temp{ranged ? std::clamp(val, this->minimum, this->maximum) : val};
+        // Enums have a maximal range which they're allowed
+        Type temp{};
+        if constexpr (std::is_enum_v<Type>) {
+            auto const r_min = std::underlying_type_t<Type>(0);
+            auto const r_max = std::underlying_type_t<Type>(EnumMetadata<Type>::GetLast());
+            temp = Type(std::clamp(std::underlying_type_t<Type>(val), r_min, r_max));
+        } else {
+            temp = ranged ? std::clamp(val, this->minimum, this->maximum) : val;
+        }
         if (use_global) {
             std::swap(this->value, temp);
         } else {
diff --git a/src/frontend_common/config.cpp b/src/frontend_common/config.cpp
index d8ab044b2d..b44a146b38 100644
--- a/src/frontend_common/config.cpp
+++ b/src/frontend_common/config.cpp
@@ -238,33 +238,27 @@ void Config::ReadControlValues() {
 void Config::ReadMotionTouchValues() {
     Settings::values.touch_from_button_maps.clear();
     int num_touch_from_button_maps = BeginArray(std::string("touch_from_button_maps"));
-
     if (num_touch_from_button_maps > 0) {
         for (int i = 0; i < num_touch_from_button_maps; ++i) {
             SetArrayIndex(i);
-
             Settings::TouchFromButtonMap map;
             map.name = ReadStringSetting(std::string("name"), std::string("default"));
-
-            const int num_touch_maps = BeginArray(std::string("entries"));
-            map.buttons.reserve(num_touch_maps);
+            int const num_touch_maps = BeginArray(std::string("entries"));
+            map.buttons.resize(num_touch_maps);
             for (int j = 0; j < num_touch_maps; j++) {
                 SetArrayIndex(j);
-                std::string touch_mapping = ReadStringSetting(std::string("bind"));
-                map.buttons.emplace_back(std::move(touch_mapping));
+                map.buttons[j] = ReadStringSetting(std::string("bind"));
             }
             EndArray(); // entries
             Settings::values.touch_from_button_maps.emplace_back(std::move(map));
         }
     } else {
-        Settings::values.touch_from_button_maps.emplace_back(
-            Settings::TouchFromButtonMap{"default", {}});
+        Settings::values.touch_from_button_maps.emplace_back(Settings::TouchFromButtonMap{"default", {}});
         num_touch_from_button_maps = 1;
     }
     EndArray(); // touch_from_button_maps
 
-    Settings::values.touch_from_button_map_index = std::clamp(
-        Settings::values.touch_from_button_map_index.GetValue(), 0, num_touch_from_button_maps - 1);
+    Settings::values.touch_from_button_map_index = (std::min)(Settings::values.touch_from_button_map_index.GetValue(), u32(num_touch_from_button_maps - 1));
 }
 
 void Config::ReadCoreValues() {
@@ -501,15 +495,12 @@ void Config::SaveMotionTouchValues() {
     BeginArray(std::string("touch_from_button_maps"));
     for (std::size_t p = 0; p < Settings::values.touch_from_button_maps.size(); ++p) {
         SetArrayIndex(int(p));
-        WriteStringSetting(std::string("name"), Settings::values.touch_from_button_maps[p].name,
-                           std::make_optional(std::string("default")));
-
+        WriteStringSetting(std::string("name"), Settings::values.touch_from_button_maps[p].name, std::make_optional(std::string("default")));
         BeginArray(std::string("entries"));
         for (std::size_t q = 0; q < Settings::values.touch_from_button_maps[p].buttons.size();
              ++q) {
             SetArrayIndex(int(q));
-            WriteStringSetting(std::string("bind"),
-                               Settings::values.touch_from_button_maps[p].buttons[q]);
+            WriteStringSetting(std::string("bind"), Settings::values.touch_from_button_maps[p].buttons[q]);
         }
         EndArray(); // entries
     }
@@ -638,8 +629,7 @@ void Config::SaveDisabledAddOnValues() {
         BeginArray(std::string("disabled"));
         for (std::size_t j = 0; j < elem.second.size(); ++j) {
             SetArrayIndex(int(j));
-            WriteStringSetting(std::string("d"), elem.second[j],
-                               std::make_optional(std::string("")));
+            WriteStringSetting(std::string("d"), elem.second[j], std::make_optional(std::string("")));
         }
         EndArray(); // disabled
         ++i;
@@ -733,21 +723,18 @@ s64 Config::ReadIntegerSetting(const std::string& key, const std::optional<s64>
     std::string full_key = GetFullKey(key, false);
     if (!default_value.has_value()) {
         try {
-            return std::stoll(
-                std::string(config->GetValue(GetSection().c_str(), full_key.c_str(), "0")));
+            return std::stoll(std::string(config->GetValue(GetSection().c_str(), full_key.c_str(), "0")));
         } catch (...) {
             return 0;
         }
     }
 
     s64 result = 0;
-    if (config->GetBoolValue(GetSection().c_str(),
-                             std::string(full_key).append("\\default").c_str(), true)) {
+    if (config->GetBoolValue(GetSection().c_str(), std::string(full_key).append("\\default").c_str(), true)) {
         result = default_value.value();
     } else {
         try {
-            result = std::stoll(std::string(config->GetValue(
-                GetSection().c_str(), full_key.c_str(), ToString(default_value.value()).c_str())));
+            result = std::stoll(std::string(config->GetValue(GetSection().c_str(), full_key.c_str(), ToString(default_value.value()).c_str())));
         } catch (...) {
             result = default_value.value();
         }
@@ -919,14 +906,12 @@ void Config::ReadSettingGeneric(Settings::BasicSetting* const setting) {
 
     bool use_global = true;
     if (setting->Switchable() && !global) {
-        use_global =
-            ReadBooleanSetting(std::string(key).append("\\use_global"), std::make_optional(true));
+        use_global = ReadBooleanSetting(std::string(key).append("\\use_global"), std::make_optional(true));
         setting->SetGlobal(use_global);
     }
 
     if (global || !use_global) {
-        const bool is_default =
-            ReadBooleanSetting(std::string(key).append("\\default"), std::make_optional(true));
+        const bool is_default = ReadBooleanSetting(std::string(key).append("\\default"), std::make_optional(true));
         if (!is_default) {
             setting->LoadString(ReadStringSetting(key, default_value));
         } else {
@@ -1050,10 +1035,9 @@ std::string Config::GetFullKey(const std::string& key, bool skipArrayIndex) {
 
 int Config::BeginArray(const std::string& array) {
     array_stack.push_back(ConfigArray{AdjustKey(array), 0, 0});
-    const int size = config->GetLongValue(GetSection().c_str(),
-                                          GetFullKey(std::string("size"), true).c_str(), 0);
-    array_stack.back().size = size;
-    return size;
+    const int size = config->GetLongValue(GetSection().c_str(), GetFullKey(std::string("size"), true).c_str(), 0);
+    array_stack.back().size = (std::max)(0, size);
+    return array_stack.back().size;
 }
 
 void Config::EndArray() {
@@ -1071,7 +1055,7 @@ void Config::EndArray() {
         // Edge-case where the first array created doesn't have a name
         config->SetValue(GetSection().c_str(), std::string("size").c_str(), ToString(size).c_str());
     } else {
-        const auto key = GetFullKey(std::string("size"), true);
+        auto const key = GetFullKey(std::string("size"), true);
         config->SetValue(GetSection().c_str(), key.c_str(), ToString(size).c_str());
     }
 
diff --git a/src/input_common/drivers/udp_client.cpp b/src/input_common/drivers/udp_client.cpp
index fc216e3c9f..7566e6040c 100644
--- a/src/input_common/drivers/udp_client.cpp
+++ b/src/input_common/drivers/udp_client.cpp
@@ -31,8 +31,10 @@ public:
     using clock = std::chrono::system_clock;
 
     explicit Socket(const std::string& host, u16 port, SocketCallback callback_)
-        : callback(std::move(callback_)), timer(io_context),
-          socket(io_context, udp::endpoint(udp::v4(), 0)), client_id(Common::Random::Random32(0)) {
+        : callback(std::move(callback_)), timer(io_context)
+        , socket(io_context, udp::endpoint(udp::v4(), 0))
+        , client_id(Common::Random::Random32(0))
+    {
         boost::system::error_code ec{};
         auto ipv4 = boost::asio::ip::make_address_v4(host, ec);
         if (ec.value() != boost::system::errc::success) {
@@ -353,8 +355,13 @@ PadIdentifier UDPClient::GetPadIdentifier(std::size_t pad_index) const {
 }
 
 Common::UUID UDPClient::GetHostUUID(const std::string& host) const {
-    const auto ip = boost::asio::ip::make_address_v4(host);
-    const auto hex_host = fmt::format("00000000-0000-0000-0000-0000{:06x}", ip.to_uint());
+    boost::system::error_code ec{};
+    auto ip = boost::asio::ip::make_address_v4(host, ec);
+    if (ec.value() != boost::system::errc::success) {
+        LOG_ERROR(Input, "Invalid IPv4 address \"{}\" provided", host);
+        ip = boost::asio::ip::address_v4{};
+    }
+    auto const hex_host = fmt::format("00000000-0000-0000-0000-0000{:06x}", ip.to_uint());
     return Common::UUID{hex_host};
 }
 
diff --git a/src/qt_common/config/uisettings.h b/src/qt_common/config/uisettings.h
index 4549a36345..d1e365553d 100644
--- a/src/qt_common/config/uisettings.h
+++ b/src/qt_common/config/uisettings.h
@@ -207,12 +207,11 @@ struct Values {
 
     // Game List
     Setting<bool> show_add_ons{linkage, true, "show_add_ons", Category::UiGameList};
-    Setting<u32> game_icon_size{linkage, 64, "game_icon_size", Category::UiGameList};
-    Setting<u32> folder_icon_size{linkage, 48, "folder_icon_size", Category::UiGameList};
+    Setting<u32, true> game_icon_size{linkage, 64, 8, 512, "game_icon_size", Category::UiGameList};
+    Setting<u32, true> folder_icon_size{linkage, 48, 8, 512, "folder_icon_size", Category::UiGameList};
     Setting<u8> row_1_text_id{linkage, 3, "row_1_text_id", Category::UiGameList};
     Setting<u8> row_2_text_id{linkage, 2, "row_2_text_id", Category::UiGameList};
-    Setting<Settings::GameListMode> game_list_mode{linkage, Settings::GameListMode::TreeView,
-                                                   "game_list_mode", Category::UiGameList};
+    Setting<Settings::GameListMode> game_list_mode{linkage, Settings::GameListMode::TreeView, "game_list_mode", Category::UiGameList};
     Setting<bool> show_game_name{linkage, true, "show_game_name", Category::UiGameList};
 
     std::atomic_bool is_game_list_reload_pending{false};
diff --git a/src/video_core/renderer_vulkan/renderer_vulkan.cpp b/src/video_core/renderer_vulkan/renderer_vulkan.cpp
index 010cfd225d..30a39ef81e 100644
--- a/src/video_core/renderer_vulkan/renderer_vulkan.cpp
+++ b/src/video_core/renderer_vulkan/renderer_vulkan.cpp
@@ -89,11 +89,10 @@ std::string BuildCommaSeparatedExtensions(
 
 } // Anonymous namespace
 
-Device CreateDevice(const vk::Instance& instance, const vk::InstanceDispatch& dld,
-                    VkSurfaceKHR surface) {
+Device CreateDevice(const vk::Instance& instance, const vk::InstanceDispatch& dld, VkSurfaceKHR surface) {
     const std::vector<VkPhysicalDevice> devices = instance.EnumeratePhysicalDevices();
-    const s32 device_index = Settings::values.vulkan_device.GetValue();
-    if (device_index < 0 || device_index >= static_cast<s32>(devices.size())) {
+    const u32 device_index = Settings::values.vulkan_device.GetValue();
+    if (device_index >= u32(devices.size())) {
         LOG_ERROR(Render_Vulkan, "Invalid device index {}!", device_index);
         throw vk::Exception(VK_ERROR_INITIALIZATION_FAILED);
     }
diff --git a/src/yuzu/configuration/configure_motion_touch.cpp b/src/yuzu/configuration/configure_motion_touch.cpp
index d1bcac12aa..2083315c03 100644
--- a/src/yuzu/configuration/configure_motion_touch.cpp
+++ b/src/yuzu/configuration/configure_motion_touch.cpp
@@ -94,11 +94,10 @@ void ConfigureMotionTouch::SetConfiguration() {
     const Common::ParamPackage touch_param(Settings::values.touch_device.GetValue());
 
     touch_from_button_maps = Settings::values.touch_from_button_maps;
-    for (const auto& touch_map : touch_from_button_maps) {
+    for (const auto& touch_map : touch_from_button_maps)
         ui->touch_from_button_map->addItem(QString::fromStdString(touch_map.name));
-    }
-    ui->touch_from_button_map->setCurrentIndex(
-        Settings::values.touch_from_button_map_index.GetValue());
+    if (auto const index = Settings::values.touch_from_button_map_index.GetValue(); int(index) < ui->touch_from_button_map->count())
+        ui->touch_from_button_map->setCurrentIndex(index);
 
     min_x = touch_param.Get("min_x", 100);
     min_y = touch_param.Get("min_y", 50);
diff --git a/src/yuzu/game/game_list.cpp b/src/yuzu/game/game_list.cpp
index 63267ddec6..521c5607f5 100644
--- a/src/yuzu/game/game_list.cpp
+++ b/src/yuzu/game/game_list.cpp
@@ -183,7 +183,7 @@ void GameList::ResetViewMode() {
         tree_view->setVisible(false);
         break;
     default:
-        break;
+        UNREACHABLE();
     }
 
     auto view = m_currentView->viewport();
@@ -196,10 +196,8 @@ void GameList::ResetViewMode() {
 
     auto scroller = QScroller::scroller(view);
     QScrollerProperties props;
-    props.setScrollMetric(QScrollerProperties::HorizontalOvershootPolicy,
-                          QScrollerProperties::OvershootAlwaysOff);
-    props.setScrollMetric(QScrollerProperties::VerticalOvershootPolicy,
-                          QScrollerProperties::OvershootAlwaysOff);
+    props.setScrollMetric(QScrollerProperties::HorizontalOvershootPolicy, QScrollerProperties::OvershootAlwaysOff);
+    props.setScrollMetric(QScrollerProperties::VerticalOvershootPolicy, QScrollerProperties::OvershootAlwaysOff);
     scroller->setScrollerProperties(props);
 
     if (m_isTreeMode != newTreeMode) {
diff --git a/src/yuzu/main_window.cpp b/src/yuzu/main_window.cpp
index 4c53ef1221..0160b74e24 100644
--- a/src/yuzu/main_window.cpp
+++ b/src/yuzu/main_window.cpp
@@ -1088,10 +1088,9 @@ void MainWindow::InitializeWidgets() {
     aa_status_button->setFocusPolicy(Qt::NoFocus);
     connect(aa_status_button, &QPushButton::clicked, [&] {
         auto aa_mode = Settings::values.anti_aliasing.GetValue();
-        aa_mode = static_cast<Settings::AntiAliasing>(static_cast<u32>(aa_mode) + 1);
-        if (aa_mode == Settings::AntiAliasing::MaxEnum) {
-            aa_mode = Settings::AntiAliasing::None;
-        }
+        aa_mode = Settings::AntiAliasing(u32(aa_mode) + 1);
+        if (u32(aa_mode) > u32(Settings::EnumMetadata<Settings::AntiAliasing>::GetLast()))
+            aa_mode = Settings::EnumMetadata<Settings::AntiAliasing>::GetFirst();
         Settings::values.anti_aliasing.SetValue(aa_mode);
         aa_status_button->setChecked(true);
         UpdateAAText();
@@ -3623,10 +3622,9 @@ void MainWindow::OnIncreaseVolume() {
 
 void MainWindow::OnToggleAdaptingFilter() {
     auto filter = Settings::values.scaling_filter.GetValue();
-    filter = static_cast<Settings::ScalingFilter>(static_cast<u32>(filter) + 1);
-    if (filter == Settings::ScalingFilter::MaxEnum) {
-        filter = Settings::ScalingFilter::NearestNeighbor;
-    }
+    filter = Settings::ScalingFilter(u32(filter) + 1);
+    if (u32(filter) > u32(Settings::EnumMetadata<Settings::ScalingFilter>::GetLast()))
+        filter = Settings::EnumMetadata<Settings::ScalingFilter>::GetFirst();
     Settings::values.scaling_filter.SetValue(filter);
     filter_status_button->setChecked(true);
     UpdateFilterText();
diff --git a/tools/README.md b/tools/README.md
index 367a00f246..d4f5aa1baa 100644
--- a/tools/README.md
+++ b/tools/README.md
@@ -28,6 +28,8 @@ Tools for Eden and other subprojects. When adding new scripts please use `#!/bin
 - `clang-format.sh`: Runs `clang-format` on the entire codebase.
     * Requires: clang
 - `find-unused-strings.sh`: Find any unused strings in the Android app (XML -> Kotlin).
+- `cpp-lint.sh`: Homemade dumb C++ linter.
+- `fuzzsettings.cpp`: Fuzz settings files.
 
 ## Android
 It's recommended to run these scritps after almost any Android change, as they are relatively fast and important both for APK bloat and CI.
diff --git a/tools/fuzzsettings.cpp b/tools/fuzzsettings.cpp
new file mode 100644
index 0000000000..e9685ce9f4
--- /dev/null
+++ b/tools/fuzzsettings.cpp
@@ -0,0 +1,63 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include <cstdio>
+#include <cstdlib>
+#include <cctype>
+#include <cstring>
+#include <ctime>
+#include <string>
+#include <string_view>
+
+int main(int argc, char *argv[]) {
+    std::srand(unsigned(std::time(nullptr)));
+
+    FILE *fp = std::fopen(argv[1], "rt");
+    if (fp) {
+        char line[BUFSIZ];
+        while (std::fgets(line, sizeof(line), fp)) {
+            if (line[0] == '[') {
+                std::printf("%s", line);
+            } else if (std::isspace(line[0])) {
+                std::printf("%s", line);
+            } else {
+                char *p = std::strchr(line, '=');
+                if (std::strstr(line, "\\default") == nullptr) {
+                    // not default
+                    *p = '\0';
+                    std::string new_line{line};
+                    std::string value{p + 1};
+                    if (value == "true" || value == "false") {
+                        new_line += std::string{} + "=TreufLAlse857874FJJakshjryiu475" + '\n';
+                    } else if (std::isdigit(value[0])) {
+                        if (new_line == "size"
+                        || std::strstr(new_line.c_str(), "entries\\size") != nullptr
+                        || std::strstr(new_line.c_str(), "\\size")) {
+                            new_line += "=-1\n";
+                        } else {
+                            new_line += '=' + std::to_string(int(std::rand())) + '\n';
+                        }
+                    } else {
+                        std::string_view const cset{"03832///1/1/.1/1./1./1./1.1/.1194573290uwmgjouidyhiomHMNIODASJK,POF MSHDVLJPOIuksdtpsunmghns"};
+                        std::string rst{"000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"};
+                        for (size_t i = 0; i < rst.size(); ++i)
+                            rst[i] = cset[std::rand() % cset.size()];
+
+                        //new_line += "=\"" + rst + "\"";
+                        new_line += "=" + value;
+                    }
+                    std::printf("%s", new_line.c_str());
+                } else {
+                    // yes default
+                    *p = '\0';
+                    std::string new_line{line};
+                    std::string value{p + 1};
+                    new_line += "=false\n";
+                    std::printf("%s", new_line.c_str());
+                }
+            }
+        }
+        std::fclose(fp);
+    }
+    return 0;
+}
diff --git a/tools/fuzzsettings.sh b/tools/fuzzsettings.sh
new file mode 100755
index 0000000000..7cf613dc3d
--- /dev/null
+++ b/tools/fuzzsettings.sh
@@ -0,0 +1,12 @@
+#!/bin/sh -ex
+
+# SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+ROOTDIR=$(CDPATH='' cd -- "$(dirname -- "$0")/" && pwd)
+
+touch "$2"
+
+c++ "$ROOTDIR/fuzzsettings.cpp" -o fuzzsettings
+./fuzzsettings "$1" >"$2"
+rm fuzzsettings