[PATCH v2 6/8] comctl32/listbox: Ignore certain messages and retrieve zero values with LBS_NODATA

[Gabriel Ivăncescu]

With LBS_NODATA listboxes, LB_GETTEXT always retrieves the value zero,
LB_GETITEMDATA returns zero, and LB_SETITEMDATA does nothing. However,
all of them do check for valid indices and return LB_ERR if not valid.

Signed-off-by: Gabriel Ivăncescu <gabrielopcode at gmail.com>
---

The next tests patch in the series deals with this.

 dlls/comctl32/listbox.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/dlls/comctl32/listbox.c b/dlls/comctl32/listbox.c
index 5e33466..ab01430 100644
--- a/dlls/comctl32/listbox.c
+++ b/dlls/comctl32/listbox.c
@@ -762,7 +762,8 @@ static LRESULT LISTBOX_GetText( LB_DESCR *descr, INT index, LPWSTR buffer, BOOL
     } else
     {
         if (buffer)
-            *((DWORD *)buffer) = *(DWORD *)&descr->items[index].data;
+            *((DWORD *)buffer) = (descr->style & LBS_NODATA) ? 0 :
+                                 *(DWORD *)&descr->items[index].data;
         len = sizeof(DWORD);
     }
     return len;
@@ -2635,7 +2636,7 @@ static LRESULT CALLBACK LISTBOX_WindowProc( HWND hwnd, UINT msg, WPARAM wParam,
             SetLastError(ERROR_INVALID_INDEX);
             return LB_ERR;
         }
-        return descr->items[wParam].data;
+        return (descr->style & LBS_NODATA) ? 0 : descr->items[wParam].data;
 
     case LB_SETITEMDATA:
         if (((INT)wParam < 0) || ((INT)wParam >= descr->nb_items))
@@ -2643,7 +2644,7 @@ static LRESULT CALLBACK LISTBOX_WindowProc( HWND hwnd, UINT msg, WPARAM wParam,
             SetLastError(ERROR_INVALID_INDEX);
             return LB_ERR;
         }
-        descr->items[wParam].data = lParam;
+        if (!(descr->style & LBS_NODATA)) descr->items[wParam].data = lParam;
         /* undocumented: returns TRUE, not LB_OKAY (0) */
         return TRUE;
 
-- 
2.19.1