fix: Multiple memory corruption issues

lib/libimhex/source/api/imhex_api.cpp

@@ -880,9 +880,9 @@ namespace hex {
                 s_fontSize = size;
             }
 
-            static AutoReset<std::unique_ptr<ImFontAtlas>> s_fontAtlas;
+            static AutoReset<std::shared_ptr<ImFontAtlas>> s_fontAtlas;
             void setFontAtlas(ImFontAtlas* fontAtlas) {
-                s_fontAtlas = std::unique_ptr<ImFontAtlas>(fontAtlas);
+                s_fontAtlas = std::unique_ptr<ImFontAtlas, void(*)(ImFontAtlas*)>(fontAtlas, IM_DELETE);
             }
 
             static ImFont *s_boldFont = nullptr;

lib/libimhex/source/api/theme_manager.cpp

@@ -17,18 +17,25 @@ namespace hex {
         AutoReset<std::string> s_imageTheme;
         AutoReset<std::string> s_currTheme;
 
+        std::mutex s_themeMutex;
     }
 
 
     void ThemeManager::addThemeHandler(const std::string &name, const ColorMap &colorMap, const std::function<ImColor(u32)> &getFunction, const std::function<void(u32, ImColor)> &setFunction) {
+        std::unique_lock lock(s_themeMutex);
+
         (*s_themeHandlers)[name] = { colorMap, getFunction, setFunction };
     }
 
     void ThemeManager::addStyleHandler(const std::string &name, const StyleMap &styleMap) {
+        std::unique_lock lock(s_themeMutex);
+
         (*s_styleHandlers)[name] = { styleMap };
     }
 
     void ThemeManager::addTheme(const std::string &content) {
+        std::unique_lock lock(s_themeMutex);
+
         try {
             auto theme = nlohmann::json::parse(content);
 
@@ -106,6 +113,8 @@ namespace hex {
     }
 
     void ThemeManager::changeTheme(std::string name) {
+        std::unique_lock lock(s_themeMutex);
+
         if (!s_themes->contains(name)) {
             if (s_themes->empty()) {
                 return;
@@ -168,12 +177,12 @@ namespace hex {
                     const float scale = style.needsScaling ? 1_scaled : 1.0F;
 
                     if (value.is_number_float()) {
-                        if (const auto newValue = std::get_if<float*>(&style.value); newValue != nullptr)
+                        if (const auto newValue = std::get_if<float*>(&style.value); newValue != nullptr && *newValue != nullptr)
                             **newValue = value.get<float>() * scale;
                         else
                             log::warn("Style variable '{}' was of type ImVec2 but a float was expected.", name);
                     } else if (value.is_array() && value.size() == 2 && value[0].is_number_float() && value[1].is_number_float()) {
-                        if (const auto newValue = std::get_if<ImVec2*>(&style.value); newValue != nullptr)
+                        if (const auto newValue = std::get_if<ImVec2*>(&style.value); newValue != nullptr && *newValue != nullptr)
                             **newValue = ImVec2(value[0].get<float>() * scale, value[1].get<float>() * scale);
                         else
                             log::warn("Style variable '{}' was of type float but a ImVec2 was expected.", name);
@@ -191,6 +200,8 @@ namespace hex {
                 hex::log::error("Theme '{}' has invalid image theme!", name);
                 s_imageTheme = "dark";
             }
+        } else {
+            s_imageTheme = "dark";
         }
 
         s_currTheme = name;
@@ -211,6 +222,8 @@ namespace hex {
     }
 
     void ThemeManager::reset() {
+        std::unique_lock lock(s_themeMutex);
+
         s_themes->clear();
         s_styleHandlers->clear();
         s_themeHandlers->clear();

main/gui/source/init/tasks.cpp

@@ -57,16 +57,20 @@ namespace hex::init {
         // Terminate all asynchronous tasks
         TaskManager::exit();
 
-        // Unlock font atlas so it can be deleted in case of a crash
+        // Unlock font atlas, so it can be deleted in case of a crash
-        if (ImGui::GetCurrentContext() != nullptr)
+        if (ImGui::GetCurrentContext() != nullptr) {
-            ImGui::GetIO().Fonts->Locked = false;
+            if (ImGui::GetIO().Fonts != nullptr) {
+                ImGui::GetIO().Fonts->Locked = false;
+                ImGui::GetIO().Fonts = nullptr;
+            }
+        }
 
         // Print a nice message if a crash happened while cleaning up resources
         // To the person fixing this:
         //     ALWAYS wrap static heap allocated objects inside libimhex such as std::vector, std::string, std::function, etc. in a AutoReset<T>
         //     e.g `AutoReset<std::vector<MyStruct>> m_structs;`
         //
-        //     The reason this is necessary is because each plugin / dynamic library gets its own instance of `std::allocator`
+        //     The reason this is necessary because each plugin / dynamic library gets its own instance of `std::allocator`
         //     which will try to free the allocated memory when the object is destroyed. However since the storage is static, this
         //     will happen only when libimhex is unloaded after main() returns. At this point all plugins have been unloaded already so
         //     the std::allocator will try to free memory in a heap that does not exist anymore which will cause a crash.
@@ -81,6 +85,7 @@ namespace hex::init {
         });
 
         ImHexApi::System::impl::cleanup();
+
         EventImHexClosing::post();
         EventManager::clear();
 

main/gui/source/window/window.cpp

@@ -985,7 +985,6 @@ namespace hex {
         ImGui_ImplOpenGL3_Shutdown();
         ImGui_ImplGlfw_Shutdown();
 
-        ImNodes::DestroyContext();
         ImPlot::DestroyContext();
         ImGui::DestroyContext();
     }