Issue with block table parsing in preR13

[michal-josef-spacek]

There is issue in block table parsing in preR13 Example: BLOCK1.DXF.gz BLOCK1.DWG.gz

Actual parsing:

...
blocks   0x46c (0xfffffb94) - 0x0 (0x48, 0x80000000)
...

and code in src/decode.c:

...
error |= decode_preR13_entities (blocks_start, blocks_end,
                                 blocks_start - blocks_offset, dat, dwg);
...

This doesn't work because blocks_end is 0. We need to use block_start + modified block_offset (& 0x00ffffff)

[rurban]

Yes, fixed in 16f6c1f97b20fd8fdec1c595e24d2fa81801afce But I dont trust the size calculation with the mask yet. I rather loop over the number of entities.

[michal-josef-spacek]

@rurban Thanks. I will test. FYI: Mask works for me.

[rurban]

yes, I re-introduced the mask, but renamed the field to size again. it's not an offset.

[michal-josef-spacek]

@rurban great

[michal-josef-spacek]

@rurban This change doesn't work. You added num_entities to decode_preR13_entities(), but we don't know this value from R_10. In <R_10 is in header. I believe that only thing how to do is while() and check entities_end value.

[michal-josef-spacek]

Something like this: https://github.com/LibreDWG/libredwg/pull/452

[michal-josef-spacek]

Fix for this issue: https://github.com/LibreDWG/libredwg/pull/559