wintab32: Don't return information for non existent cursors.

dlls/winex11.drv/wintab.c

@@ -1129,6 +1129,14 @@ UINT X11DRV_WTInfoW(UINT wCategory, UINT nIndex, LPVOID lpOutput)
         case WTI_CURSORS+7:
         case WTI_CURSORS+8:
         case WTI_CURSORS+9:
+            if (wCategory - WTI_CURSORS >= gNumCursors)
+            {
+                rc = 0;
+                WARN("Requested cursor information for non existent cursor %d; only %d cursors\n",
+                        wCategory - WTI_CURSORS, gNumCursors);
+            }
+            else
+            {
                 tgtcursor = &gSysCursor[wCategory - WTI_CURSORS];
                 switch (nIndex)
                 {
@@ -1219,6 +1227,7 @@ UINT X11DRV_WTInfoW(UINT wCategory, UINT nIndex, LPVOID lpOutput)
                         FIXME("WTI_CURSORS unhandled index %i\n",nIndex);
                         rc = 0;
                 }
+            }
             break;
         case WTI_DEVICES:
             switch (nIndex)