[RAPPS] Don't display duplicate uninstall entries when WoW64 keys are unsupported (#8253)

This only happens on 64-bit because 32-bit was being conservative.

base/applications/rapps/appdb.cpp

@@ -18,6 +18,48 @@ static HKEY g_RootKeyEnum[3] = {HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, HKEY_LOCA
 static REGSAM g_RegSamEnum[3] = {0, KEY_WOW64_32KEY, KEY_WOW64_64KEY};
 #define UNINSTALL_SUBKEY L"Software\\Microsoft\\Windows\\CurrentVersion\\Uninstall"
 
+static inline HKEY
+GetRootKeyInfo(UINT Index, REGSAM &RegSam)
+{
+    C_ASSERT(_countof(g_RootKeyEnum) == _countof(g_RegSamEnum));
+    if (Index < _countof(g_RootKeyEnum))
+    {
+        RegSam = g_RegSamEnum[Index];
+        return g_RootKeyEnum[Index];
+    }
+    return NULL;
+}
+
+class CEnumInstalledRootKey
+{
+    // HKCU + HKLM (Native) + HKLM (WoW64)
+    // Note that HKEY_CURRENT_USER\Software does not have a redirect
+    // https://learn.microsoft.com/en-us/windows/win32/winprog64/shared-registry-keys#redirected-shared-and-reflected-keys-under-wow64
+
+    UINT m_Count;
+    UINT m_Index = 0;
+
+public:
+    CEnumInstalledRootKey()
+    {
+        // We don't want to display duplicate entries on systems without WoW64 keys support.
+        // When ROS starts supporting the WOW REGSAM flags,
+        // this code can be changed back to IsSystem64Bit() ? 3 : 2.
+        m_Count = 2 + !IsSameRegKey(HKEY_LOCAL_MACHINE, UNINSTALL_SUBKEY, KEY_WOW64_64KEY,
+                                                        UNINSTALL_SUBKEY, KEY_WOW64_32KEY);
+    }
+
+    HKEY GetNext(REGSAM &RegSam)
+    {
+        return m_Index < m_Count ? GetRootKeyInfo(m_Index++, RegSam) : NULL;
+    }
+
+    UINT GetKeyIndex() const
+    {
+        return m_Index;
+    }
+};
+
 static VOID
 ClearList(CAtlList<CAppInfo *> &list)
 {
@@ -150,30 +192,6 @@ CAppDB::UpdateAvailable()
     EnumerateFiles();
 }
 
-static inline HKEY
-GetRootKeyInfo(UINT Index, REGSAM &RegSam)
-{
-    C_ASSERT(_countof(g_RootKeyEnum) == _countof(g_RegSamEnum));
-    if (Index < _countof(g_RootKeyEnum))
-    {
-        RegSam = g_RegSamEnum[Index];
-        return g_RootKeyEnum[Index];
-    }
-    return NULL;
-}
-
-HKEY
-CAppDB::EnumInstalledRootKey(UINT Index, REGSAM &RegSam)
-{
-    // Loop for through all combinations.
-    // Note that HKEY_CURRENT_USER\Software does not have a redirect
-    // https://learn.microsoft.com/en-us/windows/win32/winprog64/shared-registry-keys#redirected-shared-and-reflected-keys-under-wow64
-    if (Index < (IsSystem64Bit() ? 3 : 2))
-        return GetRootKeyInfo(Index, RegSam);
-    else
-        return NULL;
-}
-
 CInstalledApplicationInfo *
 CAppDB::CreateInstalledAppByRegistryKey(LPCWSTR KeyName, HKEY hKeyParent, UINT KeyIndex)
 {
@@ -209,7 +227,7 @@ CAppDB::EnumerateRegistry(CAtlList<CAppInfo *> *List, LPCWSTR SearchOnly)
     ATLASSERT(List || SearchOnly);
     REGSAM wowsam;
     HKEY hRootKey;
-    for (UINT rki = 0; (hRootKey = EnumInstalledRootKey(rki, wowsam)); ++rki)
+    for (CEnumInstalledRootKey RootEnum; (hRootKey = RootEnum.GetNext(wowsam)) != NULL;)
     {
         CRegKey hKey;
         if (hKey.Open(hRootKey, UNINSTALL_SUBKEY, KEY_READ | wowsam) != ERROR_SUCCESS)
@@ -227,7 +245,7 @@ CAppDB::EnumerateRegistry(CAtlList<CAppInfo *> *List, LPCWSTR SearchOnly)
             if (List || !StrCmpIW(SearchOnly, szKeyName))
             {
                 CInstalledApplicationInfo *Info;
-                Info = CreateInstalledAppByRegistryKey(szKeyName, hKey, rki);
+                Info = CreateInstalledAppByRegistryKey(szKeyName, hKey, RootEnum.GetKeyIndex());
                 if (Info)
                 {
                     if (List)

base/applications/rapps/include/appdb.h

@@ -47,8 +47,6 @@ class CAppDB
     CreateInstalledAppByRegistryKey(LPCWSTR Name);
     static CInstalledApplicationInfo *
     CreateInstalledAppInstance(LPCWSTR KeyName, BOOL User, REGSAM WowSam);
-    static HKEY
-    EnumInstalledRootKey(UINT Index, REGSAM &RegSam);
 
     size_t GetAvailableCount() const
     {

base/applications/rapps/include/misc.h

@@ -97,6 +97,8 @@ UnixTimeToFileTime(DWORD dwUnixTime, LPFILETIME pFileTime);
 BOOL
 SearchPatternMatch(LPCWSTR szHaystack, LPCWSTR szNeedle);
 
+BOOL
+IsSameRegKey(HKEY hRoot, LPCWSTR Path1, REGSAM Sam1, LPCWSTR Path2, REGSAM Sam2);
 HRESULT
 RegKeyHasValues(HKEY hKey, LPCWSTR Path, REGSAM wowsam = 0);
 LPCWSTR

base/applications/rapps/misc.cpp

@@ -10,6 +10,8 @@
 #include "rapps.h"
 #include "misc.h"
 
+EXTERN_C NTSTATUS WINAPI NtQueryObject(HANDLE, OBJECT_INFORMATION_CLASS, PVOID, ULONG, PULONG);
+
 static HANDLE hLog = NULL;
 
 UINT
@@ -452,6 +454,32 @@ UnixTimeToFileTime(DWORD dwUnixTime, LPFILETIME pFileTime)
     pFileTime->dwHighDateTime = ll >> 32;
 }
 
+static BOOL
+IsSameRegKey(HKEY hKey1, HKEY hKey2)
+{
+    // CompareObjectHandles is Win10+ so we check the path instead.
+    struct NameInfo : UNICODE_STRING
+    {
+        WCHAR Allocation[MAX_PATH];
+        NameInfo() { MaximumLength = sizeof(Allocation); Buffer = Allocation; }
+    };
+    NameInfo Name1, Name2;
+    ULONG Length;
+    return NT_SUCCESS(NtQueryObject(hKey1, ObjectNameInformation, &Name1, sizeof(Name1), &Length)) &&
+           NT_SUCCESS(NtQueryObject(hKey2, ObjectNameInformation, &Name2, sizeof(Name2), &Length)) &&
+           RtlCompareUnicodeString(&Name1, &Name2, TRUE) == 0;
+}
+
+BOOL
+IsSameRegKey(HKEY hRoot, LPCWSTR Path1, REGSAM Sam1, LPCWSTR Path2, REGSAM Sam2)
+{
+    REGSAM WowMask = KEY_WOW64_32KEY | KEY_WOW64_64KEY;
+    CRegKey key1, key2;
+    return key1.Open(hRoot, Path1, MAXIMUM_ALLOWED | (Sam1 & WowMask)) == ERROR_SUCCESS &&
+           key2.Open(hRoot, Path2, MAXIMUM_ALLOWED | (Sam2 & WowMask)) == ERROR_SUCCESS &&
+           IsSameRegKey(key1, key2);
+}
+
 HRESULT
 RegKeyHasValues(HKEY hKey, LPCWSTR Path, REGSAM wowsam)
 {