1177743 - WM_WINDOWPOSCHANGED messages that get deferred will effectively ignore any constants used for hWndInsertAfter.

Status: NEW

(Core :: IPC, defect)

Description

[Bob Owen (:bobowen)]

If we defer WM_WINDOWPOSCHANGED messages, when we process them and turn them back into SetWindowPos calls we call IsWindow [1] on the stored hWndInsertAfter parameter and ignore it, if it is not a window.

This parameter can also contain certain constants that have different meanings and are not window handles, so these will get ignored.

[1] https://hg.mozilla.org/mozilla-central/file/0b2f5e8b7be5/ipc/glue/WindowsMessageLoop.cpp#l1332

Comment 1

[Jens Stutte [:jstutte]]

The code there seems unchanged since then, so this might still be relevant. But it lives in the IPC component.