From 8c830f61a85e634b1fc135f6fe90a1dd5e45d158 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gabriel=20Iv=C4=83ncescu?= <gabrielopcode@gmail.com>
Date: Mon, 22 Jul 2019 15:29:25 +0300
Subject: [PATCH] user32/focus: Prevent a recursive loop with the activation
 messages
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When activating a window and sending activation messages to the window
procedure, Windows avoids a recursive loop by not sending more of these
messages or hooks while it's still activating the window. Some applications
actually depend on this behavior, so it is needed.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=46274
Signed-off-by: Gabriel Ivăncescu <gabrielopcode@gmail.com>
---
 dlls/win32u/input.c          | 42 +++++++++++++++++++++++++-----------
 dlls/win32u/ntuser_private.h |  1 +
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/dlls/win32u/input.c b/dlls/win32u/input.c
index cbdd4b195d3..241d07cefd2 100644
--- a/dlls/win32u/input.c
+++ b/dlls/win32u/input.c
@@ -1810,7 +1810,7 @@ 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)
@@ -1819,16 +1819,24 @@ static BOOL set_active_window( HWND hwnd, HWND *prev, BOOL mouse, BOOL focus )
         goto done;
     }
 
-    /* call CBT hook chain */
-    cbt.fMouse     = mouse;
-    cbt.hWndActive = previous;
-    if (call_hooks( WH_CBT, HCBT_ACTIVATE, (WPARAM)hwnd, (LPARAM)&cbt, sizeof(cbt) )) 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, sizeof(cbt) ))
+            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 )
@@ -1848,7 +1856,11 @@ 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, 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;
@@ -1880,7 +1892,7 @@ 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,
@@ -1914,9 +1926,13 @@ static BOOL set_active_window( HWND hwnd, HWND *prev, BOOL mouse, BOOL focus )
         }
     }
 
+clear_flags:
+    win_set_flags(hwnd, 0, WIN_IS_IN_ACTIVATION);
+
 done:
     if (hwnd) clip_fullscreen_window( hwnd, FALSE );
-    return TRUE;
+
+    return ret;
 }
 
 /**********************************************************************
diff --git a/dlls/win32u/ntuser_private.h b/dlls/win32u/ntuser_private.h
index b39e38db5d6..4be55209265 100644
--- a/dlls/win32u/ntuser_private.h
+++ b/dlls/win32u/ntuser_private.h
@@ -100,6 +100,7 @@ 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 */
-- 
2.40.1