user32/focus: Prevent a recursive loop with the activation messages

dlls/user32/tests/msg.c

@@ -5571,7 +5571,7 @@ static void test_messages(void)
 
     ShowWindow(hwnd, SW_MINIMIZE);
     flush_events();
-    ok_sequence(WmShowMinOverlappedSeq, "ShowWindow(SW_SHOWMINIMIZED):overlapped", TRUE);
+    ok_sequence(WmShowMinOverlappedSeq, "ShowWindow(SW_SHOWMINIMIZED):overlapped", FALSE);
     flush_sequence();
 
     if (GetWindowLongW( hwnd, GWL_STYLE ) & WS_MINIMIZE)

dlls/win32u/input.c

@@ -1569,7 +1569,7 @@ static BOOL set_active_window( HWND hwnd, HWND *prev, BOOL mouse, BOOL focus )
 {
     HWND previous = get_active_window();
     BOOL ret;
-    DWORD old_thread, new_thread;
+    DWORD winflags, old_thread, new_thread;
     CBTACTIVATESTRUCT cbt;
 
     if (previous == hwnd)
@@ -1578,16 +1578,24 @@ static BOOL set_active_window( HWND hwnd, HWND *prev, BOOL mouse, BOOL focus )
         return TRUE;
     }
 
-    /* call CBT hook chain */
-    cbt.fMouse     = mouse;
-    cbt.hWndActive = previous;
-    if (call_hooks( WH_CBT, HCBT_ACTIVATE, (WPARAM)hwnd, (LPARAM)&cbt, TRUE )) return FALSE;
-
-    if (is_window( previous ))
+    /* Prevent a recursive activation loop with the activation messages */
+    winflags = win_set_flags(hwnd, WIN_IS_IN_ACTIVATION, 0);
+    if (!(winflags & WIN_IS_IN_ACTIVATION))
     {
-        send_message( previous, WM_NCACTIVATE, FALSE, (LPARAM)hwnd );
-        send_message( previous, WM_ACTIVATE,
-                      MAKEWPARAM( WA_INACTIVE, is_iconic(previous) ), (LPARAM)hwnd );
+        ret = FALSE;
+
+        /* call CBT hook chain */
+        cbt.fMouse     = mouse;
+        cbt.hWndActive = previous;
+        if (call_hooks( WH_CBT, HCBT_ACTIVATE, (WPARAM)hwnd, (LPARAM)&cbt, TRUE ))
+            goto clear_flags;
+
+        if (is_window(previous))
+        {
+            send_message( previous, WM_NCACTIVATE, FALSE, (LPARAM)hwnd );
+            send_message( previous, WM_ACTIVATE,
+                          MAKEWPARAM( WA_INACTIVE, is_iconic(previous) ), (LPARAM)hwnd );
+        }
     }
 
     SERVER_START_REQ( set_active_window )
@@ -1607,7 +1615,11 @@ static BOOL set_active_window( HWND hwnd, HWND *prev, BOOL mouse, BOOL focus )
         if (send_message( hwnd, WM_QUERYNEWPALETTE, 0, 0 ))
             send_message_timeout( HWND_BROADCAST, WM_PALETTEISCHANGING, (WPARAM)hwnd, 0,
                                   SMTO_ABORTIFHUNG, 2000, NULL, FALSE );
-        if (!is_window(hwnd)) return FALSE;
+        if (!is_window(hwnd))
+        {
+            ret = FALSE;
+            goto clear_flags;
+        }
     }
 
     old_thread = previous ? get_window_thread( previous, NULL ) : 0;
@@ -1639,7 +1651,7 @@ static BOOL set_active_window( HWND hwnd, HWND *prev, BOOL mouse, BOOL focus )
         }
     }
 
-    if (is_window(hwnd))
+    if (!(winflags & WIN_IS_IN_ACTIVATION) && is_window(hwnd))
     {
         send_message( hwnd, WM_NCACTIVATE, hwnd == NtUserGetForegroundWindow(), (LPARAM)previous );
         send_message( hwnd, WM_ACTIVATE,
@@ -1666,12 +1678,15 @@ static BOOL set_active_window( HWND hwnd, HWND *prev, BOOL mouse, BOOL focus )
         /* Do not change focus if the window is no more active */
         if (hwnd == info.hwndActive)
         {
+            /* this line exists to keep this patch from applying in the wrong place */
             if (!info.hwndFocus || !hwnd || NtUserGetAncestor( info.hwndFocus, GA_ROOT ) != hwnd)
                 set_focus_window( hwnd );
         }
     }
 
-    return TRUE;
+clear_flags:
+    win_set_flags(hwnd, 0, WIN_IS_IN_ACTIVATION);
+    return ret;
 }
 
 /**********************************************************************

dlls/win32u/ntuser_private.h

@@ -105,6 +105,7 @@ typedef struct tagWND
 #define WIN_NEEDS_SHOW_OWNEDPOPUP 0x0020 /* WM_SHOWWINDOW:SC_SHOW must be sent in the next ShowOwnedPopup call */
 #define WIN_CHILDREN_MOVED        0x0040 /* children may have moved, ignore stored positions */
 #define WIN_HAS_IME_WIN           0x0080 /* the window has been registered with imm32 */
+#define WIN_IS_IN_ACTIVATION      0x0100 /* the window is in an activation process */
 
 #define WND_OTHER_PROCESS ((WND *)1)  /* returned by get_win_ptr on unknown window handles */
 #define WND_DESKTOP       ((WND *)2)  /* returned by get_win_ptr on the desktop window */