Example (created in R14):
[DIM1.scr.gz](https://github.com/LibreDWG/libredwg/files/10445175/DIM1.scr.gz)
[DIM1.DXF.gz](https://github.com/LibreDWG/libredwg/files/10445176/DIM1.DXF.gz)
[DIM1.DWG.gz](https://github.com/LibreDWG/libredwg/files/10445177/DIM1.DWG.gz)

```
Add entity DIMENSION_ANG2LN [13] ===========================
Entity number: 13, Type: 23, Addr: 6cf
flag_r11: 0x20 [RC 0]
          HAS_HANDLING (32)
size: 105 [RS]
layer: 0 [H(RSd) 8]
opts_r11: 0x801a [RSx 0]
          HAS_FLAG (2) HAS_DXF13 (8) HAS_DXF14 (16) Warning: Unknown opts_r11 (32794)
  
handle: 0.1.5C [H 5]
block: 0 [H(RSd) 2]
def_pt: (3.000000, 2.000000, 0.000000) [3RD 10]
text_midpt: (2.000000, 2.000000) [2RD 11]
flag: 0x1 [RC 70]
=> Entity DIMENSION_ALIGNED
xline1_pt: (1.000000, 1.000000, 0.000000) [3RD 13]
xline2_pt: (3.000000, 1.000000, 0.000000) [3RD 14]
ERROR: offset 2
crc: 07DC [RSx]
```
ERROR mean: 2 bytes for index to dimstyle section
Fix preR13 dimstyle index
This is a GitHub Issue
repo:libredwg
owner:LibreDWG
Title : Fix preR13 dimstyle index
Issue date:

--- start body ---
Example (created in R14):
[DIM1.scr.gz](https://github.com/LibreDWG/libredwg/files/10445175/DIM1.scr.gz)
[DIM1.DXF.gz](https://github.com/LibreDWG/libredwg/files/10445176/DIM1.DXF.gz)
[DIM1.DWG.gz](https://github.com/LibreDWG/libredwg/files/10445177/DIM1.DWG.gz)

```
Add entity DIMENSION_ANG2LN [13] ===========================
Entity number: 13, Type: 23, Addr: 6cf
flag_r11: 0x20 [RC 0]
          HAS_HANDLING (32)
size: 105 [RS]
layer: 0 [H(RSd) 8]
opts_r11: 0x801a [RSx 0]
          HAS_FLAG (2) HAS_DXF13 (8) HAS_DXF14 (16) Warning: Unknown opts_r11 (32794)
  
handle: 0.1.5C [H 5]
block: 0 [H(RSd) 2]
def_pt: (3.000000, 2.000000, 0.000000) [3RD 10]
text_midpt: (2.000000, 2.000000) [2RD 11]
flag: 0x1 [RC 70]
=> Entity DIMENSION_ALIGNED
xline1_pt: (1.000000, 1.000000, 0.000000) [3RD 13]
xline2_pt: (3.000000, 1.000000, 0.000000) [3RD 14]
ERROR: offset 2
crc: 07DC [RSx]
```
ERROR mean: 2 bytes for index to dimstyle section
--- end body ---

None