[PATCH v4 06/10] shell32/autocomplete: Dynamically allocate hwndText so it can handle arbitrary sizes

[Huw Davies]

On Mon, Sep 10, 2018 at 10:09:36PM +0300, Gabriel Ivăncescu wrote:
> Signed-off-by: Gabriel Ivăncescu <gabrielopcode at gmail.com>
> ---
>  dlls/shell32/autocomplete.c | 31 ++++++++++++++++++-------------
>  1 file changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/dlls/shell32/autocomplete.c b/dlls/shell32/autocomplete.c
> index 6f97665..7421679 100644
> --- a/dlls/shell32/autocomplete.c
> +++ b/dlls/shell32/autocomplete.c
> @@ -134,10 +134,11 @@ static LRESULT APIENTRY ACEditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam,
>  {
>      IAutoCompleteImpl *This = GetPropW(hwnd, autocomplete_propertyW);
>      HRESULT hr;
> -    WCHAR hwndText[255];
> +    WCHAR *hwndText;
> +    UINT len, size, cpt;
>      RECT r;
>      BOOL displayall = FALSE;
> -    int cpt, height, sel;
> +    int height, sel;
>  
>      if (!This->enabled) return CallWindowProcW(This->wpOrigEditProc, hwnd, uMsg, wParam, lParam);
>  
> @@ -154,10 +155,11 @@ static LRESULT APIENTRY ACEditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam,
>              }
>              return CallWindowProcW(This->wpOrigEditProc, hwnd, uMsg, wParam, lParam);
>          case WM_KEYUP:
> -        {
> -            int len;
> -
> -            GetWindowTextW(hwnd, hwndText, ARRAY_SIZE(hwndText));
> +            len = SendMessageW(hwnd, WM_GETTEXTLENGTH, 0, 0);
> +            size = len + 1;
> +            if (!(hwndText = heap_alloc(size * sizeof(WCHAR))))
> +                return 0;
> +            len = SendMessageW(hwnd, WM_GETTEXT, size, (LPARAM)hwndText);
>  
>              switch(wParam) {
>                  case VK_RETURN:
> @@ -165,7 +167,6 @@ static LRESULT APIENTRY ACEditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam,
>                      if (This->quickComplete && (GetKeyState(VK_CONTROL) & 0x8000))
>                      {
>                          WCHAR *buf;
> -                        size_t len = strlenW(hwndText);
>                          size_t sz = strlenW(This->quickComplete) + 1 + len;
>                          if ((buf = heap_alloc(sz * sizeof(WCHAR))))
>                          {
> @@ -178,9 +179,11 @@ static LRESULT APIENTRY ACEditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam,
>  
>                      if (This->options & ACO_AUTOSUGGEST)
>                          ShowWindow(This->hwndListBox, SW_HIDE);
> +                    heap_free(hwndText);
>                      return 0;
>                  case VK_LEFT:
>                  case VK_RIGHT:
> +                    heap_free(hwndText);
>                      return 0;
>                  case VK_UP:
>                  case VK_DOWN:
> @@ -196,6 +199,7 @@ static LRESULT APIENTRY ACEditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam,
>                           /* We must display all the entries */
>                           displayall = TRUE;
>                      } else {
> +                        heap_free(hwndText);
>                          if (IsWindowVisible(This->hwndListBox)) {
>                              int count;
>  
> @@ -231,21 +235,23 @@ static LRESULT APIENTRY ACEditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam,
>                  case VK_BACK:
>                  case VK_DELETE:
>                      if ((! *hwndText) && (This->options & ACO_AUTOSUGGEST)) {
> +                        heap_free(hwndText);
>                          ShowWindow(This->hwndListBox, SW_HIDE);
>                          return CallWindowProcW(This->wpOrigEditProc, hwnd, uMsg, wParam, lParam);
>                      }
>                      break;
>              }
>  
> +            if (len + 1 != size)
> +                hwndText = heap_realloc(hwndText, len + 1);

(len + 1) * sizeof(WCHAR)

This is a good example of why we want small patches.  It would have
been much harder to spot that in one of your earlier versions.

Huw.