[ros-dev] [ros-diffs] [gadamopoulos] 74552: [UXTHEME] -ThemeDrawCaptionText: Try to avoid a heap allocation when getting the window caption.

[Thomas Faber]

Hi,

comments inline.

On 2017-05-15 18:05, gadamopoulos at svn.reactos.org wrote:
> --- trunk/reactos/dll/win32/uxtheme/nonclient.c	[iso-8859-1] (original)
> +++ trunk/reactos/dll/win32/uxtheme/nonclient.c	[iso-8859-1] Mon May 15 16:05:14 2017
> @@ -100,16 +100,7 @@
>      return hIcon;
>  }
>
> -WCHAR *UserGetWindowCaption(HWND hwnd)
> -{
> -    INT len = 512;
> -    WCHAR *text;
> -    text = (WCHAR*)HeapAlloc(GetProcessHeap(), 0, len  * sizeof(WCHAR));
> -    if (text) InternalGetWindowText(hwnd, text, len);
> -    return text;
> -}
> -
> -HRESULT WINAPI ThemeDrawCaptionText(PDRAW_CONTEXT pcontext, RECT* pRect, int iPartId, int iStateId, LPCWSTR pszText)
> +HRESULT WINAPI ThemeDrawCaptionText(PDRAW_CONTEXT pcontext, RECT* pRect, int iPartId, int iStateId)
>  {
>      HRESULT hr;
>      HFONT hFont = NULL;
> @@ -117,6 +108,25 @@
>      LOGFONTW logfont;
>      COLORREF textColor;
>      COLORREF oldTextColor;
> +
> +    WCHAR buffer[50];
> +    WCHAR *pszText = buffer;
> +    INT len;
> +
> +    len = InternalGetWindowText(pcontext->hWnd, NULL, 0);
> +    if (!len)
> +        return S_OK;
> +
> +    len++; /* From now on this is the size of the buffer so include the null */
> +
> +    if (len > 50)

_countof(buffer), or ARRAYSIZE, or whatever people use these days.

> +    {
> +        pszText = (WCHAR*)HeapAlloc(GetProcessHeap(), 0, len  * sizeof(WCHAR));

Unnecessary cast.

> +        if (!pszText)
> +            return E_FAIL;

Ewwww. Worst error code.


Thanks.
-Thomas