Don't call SetScrollInfo with SB_BOTH bar type.

windows/mdi.c

@@ -1677,14 +1677,14 @@ void WINAPI CalcChildScroll( HWND hwnd, INT scroll )
 			info.nMin = childRect.left;
 			info.nMax = childRect.right - clientRect.right;
 			info.nPos = clientRect.left - childRect.left;
-			SetScrollInfo(hwnd, scroll, &info, TRUE);
+			SetScrollInfo(hwnd, SB_HORZ, &info, TRUE);
 			if (scroll == SB_HORZ) break;
 			/* fall through */
 	case SB_VERT:
 			info.nMin = childRect.top;
 			info.nMax = childRect.bottom - clientRect.bottom;
 			info.nPos = clientRect.top - childRect.top;
-			SetScrollInfo(hwnd, scroll, &info, TRUE);
+			SetScrollInfo(hwnd, SB_VERT, &info, TRUE);
 			break;
     }
 }