comctl32/toolbar: Protect from NULL pointer access in TB_GETBUTTONINFOW handler.

dlls/comctl32/tests/toolbar.c

@@ -1710,12 +1710,13 @@ static void test_recalc(void)
 static void test_getbuttoninfo(void)
 {
     HWND hToolbar = NULL;
+    TBBUTTONINFOW tbiW;
+    TBBUTTONINFOA tbi;
     int i;
 
     rebuild_toolbar_with_buttons(&hToolbar);
     for (i = 0; i < 128; i++)
     {
-        TBBUTTONINFOA tbi;
         int ret;
 
         tbi.cbSize = i;
@@ -1727,6 +1728,14 @@ static void test_getbuttoninfo(void)
             compare(ret, -1, "%d");
         }
     }
+
+    /* TBIF_TEXT with NULL pszText */
+    memset(&tbiW, 0, sizeof(tbiW));
+    tbiW.cbSize = sizeof(tbiW);
+    tbiW.dwMask = TBIF_BYINDEX | TBIF_STYLE | TBIF_COMMAND | TBIF_TEXT;
+    i = SendMessageA(hToolbar, TB_GETBUTTONINFOW, 1, (LPARAM)&tbiW);
+    ok(i == 1, "Got index %d\n", i);
+
     DestroyWindow(hToolbar);
 }
 

dlls/comctl32/toolbar.c

@@ -3397,7 +3397,7 @@ TOOLBAR_GetButtonInfoT(const TOOLBAR_INFO *infoPtr, INT Id, LPTBBUTTONINFOW lpTb
                 Str_GetPtrW(lpText, lpTbInfo->pszText, lpTbInfo->cchText);
             else
                 Str_GetPtrWtoA(lpText, (LPSTR)lpTbInfo->pszText, lpTbInfo->cchText);
-        } else
+        } else if (!bUnicode || lpTbInfo->pszText)
             lpTbInfo->pszText[0] = '\0';
     }
     return nIndex;