[Bug 55464] New: user32:msg - test_EndDialog() sometimes gets an unexpected WM_WINDOWPOSCHANGED on Windows 8

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=55464

Bug ID: 55464
           Summary: user32:msg - test_EndDialog() sometimes gets an
                    unexpected WM_WINDOWPOSCHANGED on Windows 8
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: user32
          Assignee: [e-mail]
          Reporter: [e-mail]

user32:msg - test_EndDialog() sometimes gets an unexpected WM_WINDOWPOSCHANGED
on Windows 8:

msg.c:15510: Test failed: EndDialog2: 9: the msg 0x0009 was expected, but got
msg 0x0047 instead
msg.c:15510: Test failed: EndDialog2: 10: the msg 0x0008 was expected, but got
msg 0x0009 instead
msg.c:15510: Test failed: EndDialog2: 11: the msg 0x8005 was expected, but got
msg 0x0008 instead
msg.c:15510: Test failed: EndDialog2: 12: the msg 0x0007 was expected, but got
msg 0x8005 instead
msg.c:15510: Test failed: EndDialog2: 13: the msg sequence is not complete:
expected 0000 - actual 0007
msg.c:15510: Failed sequence EndDialog2:
msg.c:15510:   0: expected: winevent 800a - actual: WEH: winevent 00E001DA
0000800a 00000000 00000000
msg.c:15510:   1: expected: msg 000a - actual: parent: 00E001DA 000a wp
00000001 lp 00000000 (flags 1d)
msg.c:15510:   2: expected: msg 0046 - actual: dialog: 002C01EA
WM_WINDOWPOSCHANGING wp 00000000 lp 00ccf870 after 00000000 x 0 y 0 cx 0 cy 0
flags SWP_HIDEWINDOW|SWP_NOACTIVATE|SWP_NOZORDER|SWP_NOSIZE|SWP_NOMOVE (flags
19)
msg.c:15510:   3: expected: hook 0005 - actual: CBT: hook 5 (HCBT_ACTIVATE) wp
00e001da lp 00ccf89c
msg.c:15510:   4: expected: msg 0086 - actual: dialog: 002C01EA 0086 wp
00000000 lp 00e001da (flags 19)
msg.c:15510:   5: expected: msg 0006 - actual: dialog: 002C01EA 0006 wp
00000000 lp 00e001da (flags 19)
msg.c:15510:   6: expected: winevent 0003 - actual: WEH: winevent 00E001DA
00000003 00000000 00000000
msg.c:15510:   7: expected: msg 0046 - actual: dialog: 002C01EA
WM_WINDOWPOSCHANGING wp 00000000 lp 00ccf888 after 0001008A x 0 y 0 cx 0 cy 0
flags SWP_NOACTIVATE|SWP_NOSIZE|SWP_NOMOVE (flags 19)
msg.c:15510:   8: expected: msg 0046 - actual: dialog: 002C01EA
WM_WINDOWPOSCHANGED wp 00000000 lp 00ccf888 after 0001008A x 108 y 131 cx 156
cy 192 flags
SWP_NOACTIVATE|SWP_NOREDRAW|SWP_NOSIZE|SWP_NOMOVE|SWP_NOCLIENTSIZE|SWP_NOCLIENTMOVE
(flags 19)
msg.c:15510:   9: expected: hook 0009 - actual: dialog: 002C01EA
WM_WINDOWPOSCHANGED wp 00000000 lp 00ccf888 after 0001008A x 108 y 131 cx 156
cy 192 flags
SWP_NOACTIVATE|SWP_NOREDRAW|SWP_NOSIZE|SWP_NOMOVE|SWP_NOCLIENTSIZE|SWP_NOCLIENTMOVE
(flags 19)
msg.c:15510:   10: expected: msg 0008 - actual: CBT: hook 9 (HCBT_SETFOCUS) wp
00e001da lp 002c01ea
msg.c:15510:   11: expected: winevent 8005 - actual: dialog: 002C01EA 0008 wp
00e001da lp 00000000 (flags 19)
msg.c:15510:   12: expected: msg 0007 - actual: WEH: winevent 00E001DA 00008005
fffffffc 00000000
msg.c:15510:   13: expected: nothing - actual: parent: 00E001DA 0007 wp
002c01ea lp 00000000 (flags 3d)

See https://test.winehq.org/data/patterns.html#user32:msg

This only happened twice so far and both times on Windows 8:
* 2023-08-08 win81_newtb-w8
* 2023-08-18 win81_newtb-w8adm