Fix Mouse remains in clicked state after resizing docked windows:
The reason for the effect is the mouse hook procedure, which seems to be quite obsolete in contemporary systems: it catches the mouse messages and posts them a second time to the same window. I assume, that was ment to speed up the shifting of the splitters on "prehistoric systems" (That's what you call every system not supporting transparent windows). I see no regression without this hook.
What happens is, the hook catches the WM_LBUTTONUP message and posts it to DockingSplitter::runProc. Here, the hook is released and ReleaseCapture() is called. All fine.
But Windows fails to update its internal key state, when the WM_LBUTTONUP comes as an posted-by-a-hook message. So, if you call GetKeyState(VK_LBUTTON) after ReleaseCapture() in the original code, then it is still in a pressed state. Which confuses the Document Map later.
Fix#8285, close#8286
80c8ee59c9