r2013 section-map overflows

[epakshay]

I am using command line tool like : dwg2dxf data.dwg

I tried converting few dwg file few worked properly. But when i tried to convert a file which have multiple feautre i.e point, line and polygon, it gives an error like this:

Reading DWG file data.dwg
Section[10132]=9933, size:  4864, address: 0xfff38ca
Section[10133]=9934, size:  4256, address: 0xfff4bca
Section[10134]=9935, size:  4672, address: 0xfff5c6a

=== Data Section (Section Info 11395) ===
ERROR: bit_read_RC buffer overflow at 267997258
ERROR: bit_read_RC buffer overflow at 267997258
ERROR: bit_read_RC buffer overflow at 267997258
ERROR: bit_read_RC buffer overflow at 267997258
ERROR: Invalid Data Section Page Map type 0x0 != 0x4163003b
ERROR: Failed to decode file: data.dwg 0x100

The file was created to plot few GIS i.e location related points and the size was upto 170MB. Please help me out in this. Thanks.

[rurban]

Which DWG version exactly? can you post the header and the failing section part of the log, best with dwg2dxf - v3, thanks. Best would be the zipped dwg, sent to my email. It could be something like GH #93

[epakshay]

Hi Reini, I tried with dwg2dxf - v3, but the command does not respond. Not able to attach the zipped file here due to size limitation. Here is the attached file link of google drive.

https://drive.google.com/open?id=1INk71FysZ69HjLP4k3XypjO3eopxDAqq

Thanks

[rurban]

Looks like an address overflow to me. 0xfff5c6a is almost at the end of 32bit (RL) types. $ printf %x 267997258 ff9504a Might need to extend a few types (Dwg_Section.address) from RL to uint64_t or RLL.

But more importantly address 0xff9504a > dwgsize: 0xac38442 (180585538) libdxfrw fails with the same problem.

Suspicious sizes, probably causing the overflow: perl -anle 'if (/address/ && $F[2] > 29856) { print $_}' data_gh144.log

Section[4129]=528673, size: 7643136, address: 0x55255c3
Section[4364]=529673, size: 7643136, address: 0x6090a8c
Section[4612]=530176, size: 7643136, address: 0x6c40667
Section[4614]=530433, size: 7643136, address: 0x738f387
Section[4696]=4690, size: 29888, address: 0x7c4d227
Section[4702]=4696, size: 29920, address: 0x7c6aac7
Section[4870]=4615, size: 545856, address: 0x7f6f487
Section[4871]=7602176, size: 546048, address: 0x7ff48c7
Section[4897]=6433, size: 7643145, address: 0x80ea534
Section[5385]=5375, size: 542784, address: 0x90ccfd2
Section[5386]=7643136, size: 542976, address: 0x9151812
Section[5392]=532741, size: 7643136, address: 0x91ed05e
Section[5644]=5375, size: 546284, address: 0x9dbd32a
Section[5645]=7643136, size: 546304, address: 0x9e42916
Section[5648]=533762, size: 7643136, address: 0x9ed15b6
Section[5663]=529936, size: 7643136, address: 0xa65bf86
Section[5903]=534272, size: 7643136, address: 0xb200d36
Section[5904]=534528, size: 7643232, address: 0xb94ad36
Section[5907]=534531, size: 7643136, address: 0xc09f776
Section[6153]=535030, size: 542720, address: 0xcc192aa
Section[10066]=-175, size: 98944, address: 0xff240aa
Section[10107]=11395, size: 99488, address: 0xff9504a
Section[10108]=-2871, size: 89440, address: 0xffad4ea

[rurban]

I'm afraid you need to use the TeighaFileConverter for now. There's something wrong with the spec when reading so many sections which overflow the dwg size.

BTW, I found those problem only in r2013 DWGs, not with other versions.

[epakshay]

Ok. Thanks for the reply. How can i use TeighaFileConverter? Does it provide command line tool. I am searching for the same, but didn't find this conversion code. Can you please share its link so that i can look into its documentation too. Thanks

[rurban]

The testcases in GH #132 (also r2013) do have the same problems.

[rurban]

https://www.google.com/search?q=TeighaFileConverter finds enough. This tool exists for linux, mac, windows, and can also be used via cmdline. see e.g. dxf-roundtrip.sh

TeighaFileConverter "indir" "outdir" ACAD$VER DWF|DWG 0 1 infile(s)

[rurban]

I got now a good testcase where libdxfrw works, and libredwg fails with section gaps. Thanks @timoria21 for the CFI dwg.

Found and fixed one fatal error with 'CFI - RIC - Room v3-2.dwg'

[timoria21]

Thanks, happy to hear that these files helped you to fix some bugs.