Hello,

All of a sudden I can get emacs to crash consistently because of some rogue font lock regexp parsing between Org mode and nim-mode[1].

I have attached a test file (that's the smallest I can get to from originally ~1000 line file). I can make the crash happen on doing M-x comment-dwim on line 69 (in the test.org file) but not on line 52 and earlier lines for example.

[1]: https://github.com/nim-lang/nim-mode

It will be tricky to get an emacs -Q recipe with org and nim-mode dependencies. So while I work on getting that recipe, does the below backtrace help?

=====

Thread 1 "emacs" received signal SIGABRT, Aborted.

0x00000033e380f6ab in raise () from /lib64/libpthread.so.0

(gdb) bt

#0  0x00000033e380f6ab in raise () from /lib64/libpthread.so.0

#1  0x000000000058c8f4 in terminate_due_to_signal (sig=6, backtrace_limit=2147483647) at emacs.c:394

#2  0x00000000006232d5 in die (msg=0x723428 "charpos < 0 || (charpos >= BUF_BEG (current_buffer) && charpos <= ZV)", file=0x72313d "xdisp.c", line=2752) at alloc.c:7419

#3  0x0000000000449caa in init_iterator (it=0x7fffffff22f0, w=0x888fb60, charpos=9982, bytepos=9982, row=0x7d9e430, base_face_id=DEFAULT_FACE_ID) at xdisp.c:2751

#4  0x000000000044af1b in start_display (it=0x7fffffff22f0, w=0x888fb60, pos=...) at xdisp.c:3060

#5  0x00000000005f8e41 in line_number_display_width (w=0x888fb60, width=0x7fffffff366c, pixel_width=0x7fffffff3668) at indent.c:1976

#6  0x00000000005f8efa in Fline_number_display_width (pixelwise=...) at indent.c:2007

#7  0x000000000064ab54 in funcall_subr (subr=0x9dca60 <Sline_number_display_width>, numargs=1, args=0x7fffffff37f0) at eval.c:2841

#8  0x000000000064a6ab in Ffuncall (nargs=2, args=0x7fffffff37e8) at eval.c:2766

#9  0x000000000069f6c7 in exec_byte_code (bytestr=..., vector=..., maxdepth=..., args_template=..., nargs=2, args=0x7fffffff4050) at bytecode.c:629

#10 0x000000000064b2bd in funcall_lambda (fun=..., nargs=2, arg_vector=0x7fffffff4040) at eval.c:2967

#11 0x000000000064a6ef in Ffuncall (nargs=3, args=0x7fffffff4038) at eval.c:2768

#12 0x000000000069f6c7 in exec_byte_code (bytestr=..., vector=..., maxdepth=..., args_template=..., nargs=2, args=0x7fffffff47a0) at bytecode.c:629

#13 0x000000000064b2bd in funcall_lambda (fun=..., nargs=2, arg_vector=0x7fffffff4790) at eval.c:2967

#14 0x000000000064aef9 in apply_lambda (fun=..., args=..., count=58) at eval.c:2903

#15 0x000000000064910b in eval_sub (form=...) at eval.c:2276

#16 0x00000000006439af in Fprogn (body=...) at eval.c:455

#17 0x0000000000645977 in Flet (args=...) at eval.c:969

#18 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#19 0x0000000000646801 in internal_lisp_condition_case (var=..., bodyform=..., handlers=...) at eval.c:1303

#20 0x0000000000646293 in Fcondition_case (args=...) at eval.c:1227

#21 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#22 0x00000000006439af in Fprogn (body=...) at eval.c:455

#23 0x000000000064b729 in funcall_lambda (fun=..., nargs=1, arg_vector=0x0) at eval.c:3042

#24 0x000000000064aef9 in apply_lambda (fun=..., args=..., count=53) at eval.c:2903

#25 0x0000000000649312 in eval_sub (form=...) at eval.c:2306

#26 0x0000000000648e44 in eval_sub (form=...) at eval.c:2219

#27 0x00000000006436f6 in Fif (args=...) at eval.c:407

#28 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#29 0x00000000006439af in Fprogn (body=...) at eval.c:455

#30 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#31 0x0000000000643754 in Fif (args=...) at eval.c:410

#32 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#33 0x00000000006439af in Fprogn (body=...) at eval.c:455

#34 0x00000000006323d0 in Fsave_excursion (args=...) at editfns.c:1050

#35 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#36 0x00000000006439af in Fprogn (body=...) at eval.c:455

#37 0x0000000000645dd1 in internal_catch (tag=..., func=0x64390f <Fprogn>, arg=...) at eval.c:1097

#38 0x0000000000645d85 in Fcatch (args=...) at eval.c:1074

#39 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#40 0x00000000006439af in Fprogn (body=...) at eval.c:455

#41 0x000000000064b729 in funcall_lambda (fun=..., nargs=1, arg_vector=0x0) at eval.c:3042

#42 0x000000000064aef9 in apply_lambda (fun=..., args=..., count=44) at eval.c:2903

#43 0x0000000000649312 in eval_sub (form=...) at eval.c:2306

#44 0x00000000006435a3 in For (args=...) at eval.c:368

#45 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#46 0x00000000006436f6 in Fif (args=...) at eval.c:407

#47 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#48 0x00000000006439af in Fprogn (body=...) at eval.c:455

#49 0x0000000000645977 in Flet (args=...) at eval.c:969

#50 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#51 0x00000000006439af in Fprogn (body=...) at eval.c:455

#52 0x00000000006323d0 in Fsave_excursion (args=...) at editfns.c:1050

#53 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#54 0x00000000006439af in Fprogn (body=...) at eval.c:455

#55 0x000000000064b729 in funcall_lambda (fun=..., nargs=0, arg_vector=0x0) at eval.c:3042

#56 0x000000000064aef9 in apply_lambda (fun=..., args=..., count=37) at eval.c:2903

#57 0x0000000000649312 in eval_sub (form=...) at eval.c:2306

#58 0x0000000000648e44 in eval_sub (form=...) at eval.c:2219

#59 0x0000000000648cda in eval_sub (form=...) at eval.c:2197

#60 0x0000000000643c68 in Fsetq (args=...) at eval.c:513

#61 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#62 0x00000000006439af in Fprogn (body=...) at eval.c:455

---Type <return> to continue, or q <return> to quit---

#63 0x000000000064b729 in funcall_lambda (fun=..., nargs=0, arg_vector=0x0) at eval.c:3042

#64 0x000000000064aef9 in apply_lambda (fun=..., args=..., count=32) at eval.c:2903

#65 0x0000000000649312 in eval_sub (form=...) at eval.c:2306

#66 0x0000000000643679 in Fand (args=...) at eval.c:389

#67 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#68 0x0000000000645243 in FletX (args=...) at eval.c:876

#69 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#70 0x00000000006439af in Fprogn (body=...) at eval.c:455

#71 0x000000000064b729 in funcall_lambda (fun=..., nargs=1, arg_vector=0x0) at eval.c:3042

#72 0x000000000064aef9 in apply_lambda (fun=..., args=..., count=28) at eval.c:2903

#73 0x0000000000649312 in eval_sub (form=...) at eval.c:2306

#74 0x0000000000643679 in Fand (args=...) at eval.c:389

#75 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#76 0x0000000000645243 in FletX (args=...) at eval.c:876

#77 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#78 0x00000000006439af in Fprogn (body=...) at eval.c:455

#79 0x00000000006323d0 in Fsave_excursion (args=...) at editfns.c:1050

#80 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#81 0x00000000006439af in Fprogn (body=...) at eval.c:455

#82 0x0000000000645977 in Flet (args=...) at eval.c:969

#83 0x0000000000648ae4 in eval_sub (form=...) at eval.c:2183

#84 0x00000000006439af in Fprogn (body=...) at eval.c:455

#85 0x000000000064b729 in funcall_lambda (fun=..., nargs=1, arg_vector=0x0) at eval.c:3042

#86 0x000000000064aef9 in apply_lambda (fun=..., args=..., count=20) at eval.c:2903

#87 0x0000000000649312 in eval_sub (form=...) at eval.c:2306

#88 0x00000000006439af in Fprogn (body=...) at eval.c:455

#89 0x000000000064b729 in funcall_lambda (fun=..., nargs=0, arg_vector=0x0) at eval.c:3042

#90 0x000000000064a7f1 in Ffuncall (nargs=1, args=0x7fffffff8658) at eval.c:2780

#91 0x000000000069f6c7 in exec_byte_code (bytestr=..., vector=..., maxdepth=..., args_template=..., nargs=0, args=0x7fffffff8db0) at bytecode.c:629

#92 0x000000000064b2bd in funcall_lambda (fun=..., nargs=0, arg_vector=0x7fffffff8db0) at eval.c:2967

#93 0x000000000064a6ef in Ffuncall (nargs=1, args=0x7fffffff8da8) at eval.c:2768

#94 0x000000000069f6c7 in exec_byte_code (bytestr=..., vector=..., maxdepth=..., args_template=..., nargs=1, args=0x7fffffff9658) at bytecode.c:629

#95 0x000000000064b2bd in funcall_lambda (fun=..., nargs=1, arg_vector=0x7fffffff9650) at eval.c:2967

#96 0x000000000064a6ef in Ffuncall (nargs=2, args=0x7fffffff9648) at eval.c:2768

#97 0x00000000006403df in Ffuncall_interactively (nargs=2, args=0x7fffffff9648) at callint.c:252

#98 0x000000000064aa62 in funcall_subr (subr=0xd84260 <Sfuncall_interactively>, numargs=2, args=0x7fffffff9648) at eval.c:2821

#99 0x000000000064a6ab in Ffuncall (nargs=3, args=0x7fffffff9640) at eval.c:2766

#100 0x0000000000642951 in Fcall_interactively (function=..., record_flag=..., keys=...) at callint.c:841

#101 0x000000000064aba1 in funcall_subr (subr=0xd842a0 <Scall_interactively>, numargs=1, args=0x7fffffff9b08) at eval.c:2846

#102 0x000000000064a6ab in Ffuncall (nargs=2, args=0x7fffffff9b00) at eval.c:2766

#103 0x000000000069f6c7 in exec_byte_code (bytestr=..., vector=..., maxdepth=..., args_template=..., nargs=1, args=0x7fffffffa378) at bytecode.c:629

#104 0x000000000064b2bd in funcall_lambda (fun=..., nargs=1, arg_vector=0x7fffffffa370) at eval.c:2967

#105 0x000000000064a6ef in Ffuncall (nargs=2, args=0x7fffffffa368) at eval.c:2768

#106 0x00000000006403df in Ffuncall_interactively (nargs=2, args=0x7fffffffa368) at callint.c:252

#107 0x000000000064aa62 in funcall_subr (subr=0xd84260 <Sfuncall_interactively>, numargs=2, args=0x7fffffffa368) at eval.c:2821

#108 0x000000000064a6ab in Ffuncall (nargs=3, args=0x7fffffffa360) at eval.c:2766

#109 0x0000000000642951 in Fcall_interactively (function=..., record_flag=..., keys=...) at callint.c:841

#110 0x000000000064aba1 in funcall_subr (subr=0xd842a0 <Scall_interactively>, numargs=3, args=0x7fffffffa850) at eval.c:2846

#111 0x000000000064a6ab in Ffuncall (nargs=4, args=0x7fffffffa848) at eval.c:2766

#112 0x000000000069f6c7 in exec_byte_code (bytestr=..., vector=..., maxdepth=..., args_template=..., nargs=1, args=0x7fffffffb040) at bytecode.c:629

#113 0x000000000064b2bd in funcall_lambda (fun=..., nargs=1, arg_vector=0x7fffffffb038) at eval.c:2967

#114 0x000000000064a6ef in Ffuncall (nargs=2, args=0x7fffffffb030) at eval.c:2768

#115 0x0000000000649fa8 in call1 (fn=..., arg1=...) at eval.c:2617

#116 0x0000000000591dad in command_loop_1 () at keyboard.c:1482

#117 0x000000000064689d in internal_condition_case (bfun=0x5915d0 <command_loop_1>, handlers=..., hfun=0x590c26 <cmd_error>) at eval.c:1332

#118 0x00000000005911d5 in command_loop_2 (ignore=...) at keyboard.c:1110

#119 0x0000000000645dd1 in internal_catch (tag=..., func=0x5911ac <command_loop_2>, arg=...) at eval.c:1097

#120 0x0000000000591177 in command_loop () at keyboard.c:1089

#121 0x000000000059073b in recursive_edit_1 () at keyboard.c:695

#122 0x000000000059091a in Frecursive_edit () at keyboard.c:766

#123 0x000000000058e617 in main (argc=1, argv=0x7fffffffb538) at emacs.c:1713