bug#26531: Emacs crashes with adding space character

[Ranjan Maitra]

Hello,

I am running emacs 25.1 on a fully updated Fedora 25 linux.

I have stumbled upon the bug when editing the attached file and I can not 
figure out the issues.

In the above file, if I go to before "Usage..." and start typing anything, 
including whitespace, emacs crashes. Here is gdb output with bt full and 
backtrace.


(gdb) bt full
#0  0x000000000053af6b in re_match_2_internal ()
#1  0x000000000053850a in fast_looking_at ()
#2  0x00000000004a983b in bidi_at_paragraph_end ()
#3  0x00000000004ada9f in bidi_move_to_visually_next ()
#4  0x00000000004446b0 in set_iterator_to_next ()
#5  0x000000000044eafe in display_line ()
#6  0x0000000000451268 in try_window ()
#7  0x000000000046544e in redisplay_window ()
#8  0x000000000046852b in redisplay_window_0 ()
#9  0x00000000005644be in internal_condition_case_1 ()
#10 0x000000000043227d in redisplay_windows ()
#11 0x0000000000454dd9 in redisplay_internal ()
#12 0x00000000004fb44b in read_char ()
#13 0x00000000004fdf3d in read_key_sequence.constprop ()
#14 0x00000000004ffb84 in command_loop_1 ()
#15 0x0000000000564432 in internal_condition_case ()
#16 0x00000000004f1614 in command_loop_2 ()
#17 0x00000000005643d3 in internal_catch ()
#18 0x00000000004f15d0 in command_loop ()
#19 0x00000000004f5dd7 in recursive_edit_1 ()
#20 0x00000000004f6128 in Frecursive_edit ()
#21 0x0000000000419d52 in main ()


(gdb) backtrace
#0  0x000000000053af6b in re_match_2_internal ()
#1  0x000000000053850a in fast_looking_at ()
#2  0x00000000004a983b in bidi_at_paragraph_end ()
#3  0x00000000004ada9f in bidi_move_to_visually_next ()
#4  0x00000000004446b0 in set_iterator_to_next ()
#5  0x000000000044eafe in display_line ()
#6  0x0000000000451268 in try_window ()
#7  0x000000000046544e in redisplay_window ()
#8  0x000000000046852b in redisplay_window_0 ()
#9  0x00000000005644be in internal_condition_case_1 ()
#10 0x000000000043227d in redisplay_windows ()
#11 0x0000000000454dd9 in redisplay_internal ()
#12 0x00000000004fb44b in read_char ()
#13 0x00000000004fdf3d in read_key_sequence.constprop ()
#14 0x00000000004ffb84 in command_loop_1 ()
#15 0x0000000000564432 in internal_condition_case ()
#16 0x00000000004f1614 in command_loop_2 ()
#17 0x00000000005643d3 in internal_catch ()
#18 0x00000000004f15d0 in command_loop ()
#19 0x00000000004f5dd7 in recursive_edit_1 ()
#20 0x00000000004f6128 in Frecursive_edit ()
#21 0x0000000000419d52 in main ()


Note that I have no command for xbacktrace.
(gdb) xbacktrace
Undefined command: "xbacktrace".  Try "help".

This has really been a major block for me. So, I was wondering if anyone can 
help track down the error.

Please feel free to ask questions if something is not clear.

Thanks again! 

Best wishes,
Ranjan



-- 
Ranjan Maitra <maitra@gmx.com>

temp.c
Description: Text document