In https://github.com/LibreDWG/libredwg/blob/master/src/dwg.spec#L1167 we have:
```
    if (R11OPTS (1))
      FIELD_RC (has_vertex, 66);
```
This is bad, it's
```
    if (R11OPTS (1))
      FIELD_RC (flag, 70);
```
Same flag as https://github.com/LibreDWG/libredwg/blob/master/include/dwg.h#L1545:
```
BITCODE_BS flag;        /* 1: closed, 2: curve_fit, 4: spline_fit, 8: 3d, 0x10: 3dmesh,
                             0x20: mesh_closed_in_n, 0x40: polyface_mesh, 0x80: ltype_continuous */
```
Not short, but byte in preR13.
In preR13 are used only 1 (closed) and 2 (curve_fit) probably

Fix polyline flag in preR13
This is a GitHub Issue
repo:libredwg
owner:LibreDWG
Title : Fix polyline flag in preR13
Issue date:

--- start body ---
In https://github.com/LibreDWG/libredwg/blob/master/src/dwg.spec#L1167 we have:
```
    if (R11OPTS (1))
      FIELD_RC (has_vertex, 66);
```
This is bad, it's
```
    if (R11OPTS (1))
      FIELD_RC (flag, 70);
```
Same flag as https://github.com/LibreDWG/libredwg/blob/master/include/dwg.h#L1545:
```
BITCODE_BS flag;        /* 1: closed, 2: curve_fit, 4: spline_fit, 8: 3d, 0x10: 3dmesh,
                             0x20: mesh_closed_in_n, 0x40: polyface_mesh, 0x80: ltype_continuous */
```
Not short, but byte in preR13.
In preR13 are used only 1 (closed) and 2 (curve_fit) probably

--- end body ---
