Some code ambiguity in tab control code.

[John Found]

Hi.

Trying without success to show tooltips for a tabcontrol, I found the following problems in the source code. Notice, that my skills in C++ are poor, so it is very possible the following is a false alarm.

I am quote https://github.com/wine-mirror/wine/blob/master/dlls/comctl32/tab.c (hope it is the proper source code)

This seems to be a bug: WM_LBUTTONDOWN is relayed in the WM_MOUSEMOVE handler. But WM_LBUTTONDOWN will always hide the tooltip. WM_MOUSEMOVE instead will set the timer for showing the tooltip.
> static LRESULT
> TAB_MouseMove (TAB_INFO *infoPtr, WPARAM wParam, LPARAM lParam)
> {
>   int redrawLeave;
>   int redrawEnter;
>
> if (infoPtr->hwndToolTip)
>     TAB_RelayEvent (infoPtr->hwndToolTip, infoPtr->hwnd,
>    	    WM_LBUTTONDOWN, wParam, lParam);
>
> /* Determine which tab to highlight.  Redraw tabs which change highlight
>   ** status. */
>   TAB_RecalcHotTrack(infoPtr, &lParam, &redrawLeave, &redrawEnter);
>
> hottrack_refresh (infoPtr, redrawLeave);
>   hottrack_refresh (infoPtr, redrawEnter);
>
> return 0;
> }

The WM_LBUTTONDOWN is relayed twice? Why? It is not exactly a bug, but sub-optimal.
> static LRESULT
> TAB_LButtonDown (TAB_INFO *infoPtr, WPARAM wParam, LPARAM lParam)
> {
>   POINT pt;
>   INT newItem;
>   UINT dummy;
>
> if (infoPtr->hwndToolTip)
>     TAB_RelayEvent (infoPtr->hwndToolTip, infoPtr->hwnd,
>    	    WM_LBUTTONDOWN, wParam, lParam);
>
> if (!(infoPtr->dwStyle & TCS_FOCUSNEVER)) {
>     SetFocus (infoPtr->hwnd);
>   }
>
> if (infoPtr->hwndToolTip)
>     TAB_RelayEvent (infoPtr->hwndToolTip, infoPtr->hwnd,
>    	    WM_LBUTTONDOWN, wParam, lParam);