rewrite shortcut management code with RAII, error logging and exceptions

It actually works now.

plugins/windows-notification/api/include/ComPtr.hpp

@@ -1,18 +0,0 @@
-#pragma once
-
-template<typename T>
-struct ComPtr
-{
-    T *p{};
-
-    ~ComPtr() { if (p != nullptr) p->Release(); }
-
-    T  &operator*() const { return *p; }
-    T **operator&() const { return &p; }
-    T **operator&()       { return &p; }
-    T *operator->() const { return  p; }
-
-    template<typename U>
-    HRESULT As( U **const pp ) const
-    { return p->QueryInterface(pp); }
-};

plugins/windows-notification/api/src/shortcutcreator.cpp

@@ -1,151 +1,107 @@
-#include <shlobj.h>
-#include <memory>
 
 #include "shortcutcreator.h"
 #include "win32.hpp"
 #include "converter.hpp"
 #include "ginvoke.hpp"
 
-#ifdef UNICODE
-    #define _UNICODE
-#endif
-
-#include <tchar.h>        // magic
 #include <objbase.h>      // COM stuff
 #include <shlobj.h>       // IShellLink
 #include <propvarutil.h>  // InitPropVariantFromString
 #include <propkey.h>      // PKEY_AppUserModel_ID
-#include <cstdio>         // 'cause iostreams are bloat
+#include <winrt/base.h>   // At least one COM header must have been previously
-#include <filesystem>
+// included, for `winrt::create_instance` to work with the `GUID` type.
 
-#include "ComPtr.hpp"
+#include <memory>
 
-// Not available in MINGW headers for some reason
+namespace {
-PSSTDAPI PropVariantToString(_In_ REFPROPVARIANT propvar, _Out_writes_(cch) PWSTR psz, _In_ UINT cch);
 
-int32_t InstallShortcut(const std::wstring& exe_path, const std::wstring& aumid, const std::wstring& shortcut_path)
+#define checked(func, args) \
+    if (const auto hr = ((func)args); FAILED(hr)) \
+    { \
+        g_warning("%s%s failed: hresult %#08" PRIX32, \
+            #func, #args, static_cast<std::uint32_t>(hr)); \
+        winrt::throw_hresult(hr); \
+    }
+
+struct property
 {
-    ComPtr<IShellLink> shellLink;
+    property() noexcept : var{} {}
-    auto hr = CoCreateInstance(CLSID_ShellLink, nullptr, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&shellLink));
 
-    if (SUCCEEDED(hr))
+    explicit property(const std::wstring &value)
     {
-        hr = shellLink->SetPath(exe_path.c_str());
+        checked(::InitPropVariantFromString,(value.c_str(), &var));
-        if (SUCCEEDED(hr))
-        {
-            hr = shellLink->SetArguments(TEXT(""));
-            if (SUCCEEDED(hr))
-            {
-                hr = shellLink->SetWorkingDirectory(exe_path.c_str());
-                if (SUCCEEDED(hr))
-                {
-                    ComPtr<IPropertyStore> propertyStore;
-                    hr = shellLink.As(&propertyStore);
-                    if (SUCCEEDED(hr))
-                    {
-                        PROPVARIANT appIdPropVar;
-                        hr = InitPropVariantFromString(aumid.c_str(), &appIdPropVar);
-                        if (SUCCEEDED(hr))
-                        {
-                            hr = propertyStore->SetValue(PKEY_AppUserModel_ID, appIdPropVar);
-                            if (SUCCEEDED(hr))
-                            {
-                                hr = propertyStore->Commit();
-                                if (SUCCEEDED(hr))
-                                {
-                                    ComPtr<IPersistFile> persistFile;
-                                    hr = shellLink.As(&persistFile);
-                                    if (SUCCEEDED(hr))
-                                    {
-                                        hr = persistFile->Save(shortcut_path.c_str(), TRUE);
     }
-                                }
-                            }
-                            PropVariantClear(&appIdPropVar);
-                        }
-                    }
-                }
-            }
-        }
-    }
-    return hr;
-}
 
-int32_t ValidateShortcut(const std::wstring& shortcut_path, const std::wstring& currentAumid)
+    ~property()
+    {
+        if (const auto hr = ::PropVariantClear(&var); FAILED(hr))
+            g_critical("PropVariantClear failed: hresult %#08" PRIX32,
+                static_cast<std::uint32_t>(hr));
+    }
+
+    auto str() const
+    {
+        wchar_t *str;
+        checked(::PropVariantToStringAlloc,(var, &str));
+        return std::unique_ptr
+            <wchar_t, decltype(&::CoTaskMemFree)>
+            {    str,          &::CoTaskMemFree };
+    }
+
+    operator const PROPVARIANT &() const noexcept { return  var; }
+    operator       PROPVARIANT *()       noexcept { return &var; }
+
+private:
+    PROPVARIANT var;
+};
+
+bool ImplEnsureAumiddedShortcutExists(
+    const std::string_view menu_rel_path, const std::string_view narrow_aumid)
 {
-    bool wasChanged = false;
+    const auto aumid = sview_to_wstr(narrow_aumid);
-
+    if (aumid.empty())
-    ComPtr<IShellLink> shellLink;
-    auto hr = CoCreateInstance(CLSID_ShellLink, nullptr, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&shellLink));
-
-    if (SUCCEEDED(hr))
-    {
-        ComPtr<IPersistFile> persistFile;
-        hr = shellLink.As(&persistFile);
-        if (SUCCEEDED(hr))
-        {
-            hr = persistFile->Load(shortcut_path.c_str(), STGM_READWRITE);
-            if (SUCCEEDED(hr))
-            {
-                ComPtr<IPropertyStore> propertyStore;
-                hr = shellLink.As(&propertyStore);
-                if (SUCCEEDED(hr))
-                {
-                    PROPVARIANT appIdPropVar;
-                    hr = propertyStore->GetValue(PKEY_AppUserModel_ID, &appIdPropVar);
-                    if (SUCCEEDED(hr))
-                    {
-                        std::array<wchar_t, MAX_PATH> AUMI;
-                        hr = PropVariantToString(appIdPropVar, AUMI.data(), AUMI.size());
-                        if (FAILED(hr) || currentAumid != std::wstring(AUMI.data()))
-                        {
-                            // AUMI Changed for the same app, let's update the current value! =)
-                            wasChanged = true;
-                            PropVariantClear(&appIdPropVar);
-                            hr = InitPropVariantFromString(currentAumid.c_str(), &appIdPropVar);
-                            if (SUCCEEDED(hr))
-                            {
-                                hr = propertyStore->SetValue(PKEY_AppUserModel_ID, appIdPropVar);
-                                if (SUCCEEDED(hr))
-                                {
-                                    hr = propertyStore->Commit();
-                                    if (SUCCEEDED(hr) && SUCCEEDED(persistFile->IsDirty()))
-                                    {
-                                        hr = persistFile->Save(shortcut_path.c_str(), TRUE);
-                                    }
-                                }
-                            }
-                        }
-                        PropVariantClear(&appIdPropVar);
-                    }
-                }
-            }
-        }
-    }
-    return hr;
-}
-
-static bool ImplEnsureAumiddedShortcutExists(
-    const std::string_view menu_rel_path, const std::string_view aumid)
-{
-    const auto waumid = sview_to_wstr(aumid);
-    if (waumid.empty())
     {
         return false;
     }
 
-    const auto path = GetEnv(L"APPDATA") + LR"(\Microsoft\Windows\Start Menu\)"
+    const auto exe_path = GetExePath();
+    const auto shortcut_path = GetEnv(L"APPDATA")
+        + LR"(\Microsoft\Windows\Start Menu\)"
         + sview_to_wstr(menu_rel_path) + L".lnk";
-    if (!std::filesystem::exists(path))
+
+    const auto lnk = winrt::create_instance<IShellLinkW>(CLSID_ShellLink);
+    const auto file = lnk.as<IPersistFile>();
+    const auto store = lnk.as<IPropertyStore>();
+
+    if (SUCCEEDED(file->Load(shortcut_path.c_str(), STGM_READWRITE)))
     {
-        return SUCCEEDED(InstallShortcut(GetExePath(), waumid, path));
+        property aumid_prop;
+        checked(store->GetValue,(PKEY_AppUserModel_ID, aumid_prop));
+        if (aumid_prop.str().get() != aumid)
+            checked(store->SetValue,(PKEY_AppUserModel_ID, property{aumid}));
     }
     else
     {
-        return SUCCEEDED(ValidateShortcut(path, waumid));
+        checked(store->SetValue,(PKEY_AppUserModel_ID, property{aumid}));
+        checked(lnk->SetPath,(exe_path.c_str()));
     }
+
+    checked(store->Commit,());
+
+    if (file->IsDirty() != S_FALSE)  // not the same as `== S_OK`
+    {
+        constexpr auto set_file_as_current = TRUE;
+        checked(file->Save,(shortcut_path.c_str(), set_file_as_current));
+    }
+
+    return true;
 }
 
+#undef checked
+
+}  // nameless namespace
+
+
 extern "C"
 {
     gboolean EnsureAumiddedShortcutExists(const gchar *const aumid) noexcept