[NTUSER][USER32] Rewrite GetAncestor (reactos#7978)

JIRA issue: N/A
- Set the last error.
- Check message window.
- Modify user32.spec.

Author: katahiromz

win32ss/include/ntuser.h

@@ -2138,8 +2138,8 @@ NtUserGetAltTabInfo(
 HWND
 NTAPI
 NtUserGetAncestor(
-    HWND hWnd,
-    UINT Flags);
+    _In_ HWND hWnd,
+    _In_ UINT uType);
 
 DWORD
 NTAPI

win32ss/user/ntuser/window.c

@@ -3351,99 +3351,98 @@ NtUserFindWindowEx(HWND hwndParent,
    return Ret;
 }
 
-
-/*
- * @implemented
- */
-PWND FASTCALL UserGetAncestor(PWND Wnd, UINT Type)
+/* @implemented */
+PWND FASTCALL
+UserGetAncestor(_In_ PWND pWnd, _In_ UINT uType)
 {
-   PWND WndAncestor, Parent;
+    PWND WndAncestor, Parent, pwndMessage;
+    PDESKTOP pDesktop;
+    PWND pwndDesktop;
 
-   if (UserHMGetHandle(Wnd) == IntGetDesktopWindow())
-   {
-      return NULL;
-   }
+    pDesktop = pWnd->head.rpdesk;
+    ASSERT(pDesktop);
+    ASSERT(pDesktop->pDeskInfo);
 
-   switch (Type)
-   {
-      case GA_PARENT:
-         {
-            WndAncestor = Wnd->spwndParent;
-            break;
-         }
+    pwndDesktop = pDesktop->pDeskInfo->spwnd;
+    if (pWnd == pwndDesktop)
+        return NULL;
 
-      case GA_ROOT:
-         {
-            WndAncestor = Wnd;
-            Parent = NULL;
+    pwndMessage = pDesktop->spwndMessage;
+    if (pWnd == pwndMessage)
+        return NULL;
 
-            for(;;)
-            {
-               if(!(Parent = WndAncestor->spwndParent))
-               {
-                  break;
-               }
-               if(IntIsDesktopWindow(Parent))
-               {
-                  break;
-               }
+    Parent = pWnd->spwndParent;
+    if (!Parent)
+        return NULL;
 
-               WndAncestor = Parent;
-            }
-            break;
-         }
+    switch (uType)
+    {
+        case GA_PARENT:
+            return Parent;
 
-      case GA_ROOTOWNER:
-         {
-            WndAncestor = Wnd;
+        case GA_ROOT:
+            WndAncestor = pWnd;
+            if (Parent == pwndDesktop)
+                break;
 
-            for (;;)
+            do
             {
-               Parent = IntGetParent(WndAncestor);
+                if (Parent == pwndMessage)
+                    break;
 
-               if (!Parent)
-               {
-                  break;
-               }
+                WndAncestor = Parent;
+
+                pDesktop = Parent->head.rpdesk;
+                ASSERT(pDesktop);
+                ASSERT(pDesktop->pDeskInfo);
+
+                Parent = Parent->spwndParent;
+            } while (Parent != pDesktop->pDeskInfo->spwnd);
+            break;
 
-               WndAncestor = Parent;
+        case GA_ROOTOWNER:
+            WndAncestor = pWnd;
+            for (PWND pwndNode = IntGetParent(pWnd); pwndNode; pwndNode = IntGetParent(pwndNode))
+            {
+                WndAncestor = pwndNode;
             }
             break;
-         }
 
-      default:
-         {
+        default:
             return NULL;
-         }
-   }
+    }
 
-   return WndAncestor;
+    return WndAncestor;
 }
 
-/*
- * @implemented
- */
+/* @implemented */
 HWND APIENTRY
-NtUserGetAncestor(HWND hWnd, UINT Type)
+NtUserGetAncestor(_In_ HWND hWnd, _In_ UINT uType)
 {
-   PWND Window, Ancestor;
-   HWND Ret = NULL;
+    PWND Window, pwndAncestor;
+    HWND hwndAncestor = NULL;
 
-   TRACE("Enter NtUserGetAncestor\n");
-   UserEnterExclusive();
+    TRACE("Enter NtUserGetAncestor\n");
+    UserEnterShared();
 
-   Window = UserGetWindowObject(hWnd);
-   if (Window)
-   {
-      Ancestor = UserGetAncestor(Window, Type);
-      /* fixme: can UserGetAncestor ever return NULL for a valid window? */
+    Window = UserGetWindowObject(hWnd);
+    if (!Window)
+        goto Quit;
 
-      Ret = (Ancestor ? UserHMGetHandle(Ancestor) : NULL);
-   }
+    if (!uType || uType > GA_ROOTOWNER)
+    {
+        EngSetLastError(ERROR_INVALID_PARAMETER);
+        goto Quit;
+    }
 
-   TRACE("Leave NtUserGetAncestor, ret=%p\n", Ret);
-   UserLeave();
-   return Ret;
+    pwndAncestor = UserGetAncestor(Window, uType);
+    if (pwndAncestor)
+        hwndAncestor = UserHMGetHandle(pwndAncestor);
+
+Quit:
+    UserLeave();
+    TRACE("Leave NtUserGetAncestor returning %p\n", hwndAncestor);
+    return hwndAncestor;
 }
 
 ////

win32ss/user/user32/user32.spec

@@ -249,7 +249,7 @@
 @ stdcall GetAltTabInfo(long long ptr ptr long) GetAltTabInfoA
 @ stdcall GetAltTabInfoA(long long ptr ptr long)
 @ stdcall GetAltTabInfoW(long long ptr ptr long)
-@ stdcall GetAncestor(long long) ; Direct call NtUserGetAncestor
+@ stdcall GetAncestor(ptr long) ; Direct call NtUserGetAncestor
 @ stdcall GetAppCompatFlags(long)
 @ stdcall GetAppCompatFlags2(long)
 @ stdcall GetAsyncKeyState(long)

win32ss/user/user32/windows/window.c

@@ -924,52 +924,40 @@ GetAltTabInfoW(HWND hwnd,
     return NtUserGetAltTabInfo(hwnd,iItem,pati,pszItemText,cchItemText,FALSE);
 }
 
-
-/*
- * @implemented
- */
+/* @implemented */
 HWND WINAPI
-GetAncestor(HWND hwnd, UINT gaFlags)
+GetAncestor(_In_ HWND hwnd, _In_ UINT uType)
 {
-    HWND Ret = NULL;
-    PWND Ancestor, Wnd;
-
-    Wnd = ValidateHwnd(hwnd);
-    if (!Wnd)
+    PWND pWnd = ValidateHwnd(hwnd);
+    if (!pWnd || pWnd == GetThreadDesktopWnd())
         return NULL;
 
-    _SEH2_TRY
+    /* Special handling optimized for speed */
+    if (uType == GA_PARENT)
     {
-        Ancestor = NULL;
-        switch (gaFlags)
-        {
-            case GA_PARENT:
-                if (Wnd->spwndParent != NULL)
-                    Ancestor = DesktopPtrToUser(Wnd->spwndParent);
-                break;
+        HWND hwndAncestor = NULL;
 
-            default:
-                /* FIXME: Call win32k for now */
-                Wnd = NULL;
-                break;
+        _SEH2_TRY
+        {
+            if (pWnd->spwndParent && pWnd->fnid != FNID_MESSAGEWND)
+            {
+                PWND pwndAncestor = DesktopPtrToUser(pWnd->spwndParent);
+                if (pwndAncestor)
+                    hwndAncestor = UserHMGetHandle(pwndAncestor);
+            }
+        }
+        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+        {
+            /* Do nothing */
         }
+        _SEH2_END;
 
-        if (Ancestor != NULL)
-            Ret = UserHMGetHandle(Ancestor);
+        return hwndAncestor;
     }
-    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
-    {
-        /* Do nothing */
-    }
-    _SEH2_END;
 
-    if (!Wnd) /* Fall back */
-        Ret = NtUserGetAncestor(hwnd, gaFlags);
-
-    return Ret;
+    return NtUserGetAncestor(hwnd, uType);
 }
 
-
 /*
  * @implemented
  */