Segmentation fault with textord_blockndoc_fixed=1

[jbarth-ubhd]

Current Behavior

tesseract 00178917.tif 00178917-b -l deu+eng+fra+ita+script/Latin -c invert_threshold=0 --dpi 230 alnum monofriendly
Detected 9 diacritics
Segmentation fault (core dumped)

> cat alnum
tessedit_char_whitelist zyxwvutsrqponmlkjihgfedcba][ZYXWVUTSRQPONMLKJIHGFEDCBA?>=<;:9876543210/.-,+*)('&"! §°ÀÂÄÆÇÈÉÊËÎÏÔÖÙÛÜßàâäæçèéêëìíîïòóôöùúûüÿČčŒœŸŽžǍǎ

> cat monofriendly | grep -v ^#
textord_blockndoc_fixed	1
textord_words_def_fixed	0.024

no segfault when not setting textord_blockndoc_fixed

segfault-00178917.zip

Expected Behavior

nice output file

Suggested Fix

No response

tesseract -v

tesseract 5.3.0
leptonica-1.79.0
libgif 5.1.4 : libjpeg 8d (libjpeg-turbo 2.0.3) : libpng 1.6.37 : libtiff 4.1.0 : zlib 1.2.11 : libwebp 0.6.1 : libopenjp2 2.5.0
Found AVX2
Found AVX
Found FMA
Found SSE4.1
Found libarchive 3.4.0 zlib/1.2.11 liblzma/5.2.4 bz2lib/1.0.8 liblz4/1.9.2 libzstd/1.4.4
Found libcurl/7.68.0 NSS/3.49.1 zlib/1.2.11 brotli/1.0.9 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh/0.9.3/openssl/zlib nghttp2/1.40.0 librtmp/2.3

Operating System

Ubuntu 20.04 Focal

Other Operating System

No response

uname -a

Linux pers16 5.4.0-144-generic #161-Ubuntu SMP Fri Feb 3 14:49:04 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

Compiler

gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

CPU

Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz

Virtualization / Containers

none

Other Information

more sample images are available on request

[stweil]

It is sufficient to run tesseract 00178917.tif - -c textord_blockndoc_fixed=1, and it also crashs with test/testing/8071_093.3B.tif.

[stweil]

Crash stack:

(gdb) i s
#0  tesseract::ERRCODE::error (this=0x555555b185b0 <tesseract::NULL_DATA>, caller=0x555555959fc4 "ELIST2_ITERATOR::data", action=tesseract::ABORT, format=0x0) at ../../../src/ccutil/errcode.cpp:87
#1  0x000055555575bdc8 in tesseract::ERRCODE::error (this=0x555555b185b0 <tesseract::NULL_DATA>, caller=0x555555959fc4 "ELIST2_ITERATOR::data", action=tesseract::ABORT) at ../../../src/ccutil/errcode.cpp:99
#2  0x00005555555b9039 in tesseract::ELIST2_ITERATOR::data (this=0x7fffffffcb60) at ../../../src/ccutil/elst2.h:194
#3  0x00005555556d1ed4 in tesseract::X_ITER<tesseract::ELIST2_ITERATOR, tesseract::TO_ROW>::data (this=0x7fffffffcb60) at ../../../src/ccutil/list.h:29
#4  0x00005555557e85bc in tesseract::try_doc_fixed (page_tr=..., port_blocks=0x7fffffffcfb8, gradient=-0.00894454401) at ../../../src/textord/topitch.cpp:409

The crash also occurs with old versions of Tesseract (tested with 4.0.0 and 5.0.0-alpha-822-gdea08).

[stweil]

This issue is fixed by commit 1569e50. Thank you @jbarth-ubhd for the report!