abort in display_line

[Per Starback]

GNU Emacs 21.1 (and also still in current cvs):

With X11:

        $ emacs-21 -q -g 40x40

The bug isn't dependent on setting the geometry.  That is only added
to make sure we have the same geometry when reproducing the bug.

        C-u 4 2 * C-x 3 C-u 1 7 C-x }

Now the right window is really narrow.  The <- truncation arrows are
right next to the -> arrows.

        C-x }

Emacs aborts!

I have done that with emacs-21 and with current cvs emacs.  The
following backtrace is with current cvs emacs.

(gdb) backtrace
#0  abort () at emacs.c:403
#1  0x0806d919 in display_line (it=0xbfffe310) at xdisp.c:13073
#2  0x08069f4b in try_window (window=1211305240, pos=
      {charpos = 1, bytepos = 1}) at xdisp.c:10644
#3  0x080693c6 in redisplay_window (window=1211305240, just_this_one_p=0)
    at xdisp.c:10312
#4  0x0806700a in redisplay_window_0 (window=1211305240) at xdisp.c:9255
#5  0x08122204 in internal_condition_case_1 (
    bfun=0x8066fe4 <redisplay_window_0>, arg=1211305240, handlers=405335076, 
    hfun=0x8066fc8 <redisplay_window_error>) at eval.c:1338
#6  0x08066faf in redisplay_windows (window=1212619088) at xdisp.c:9235
#7  0x08066f74 in redisplay_windows (window=1212092608) at xdisp.c:9229
#8  0x08066745 in redisplay_internal (preserve_echo_area=0) at xdisp.c:8835
#9  0x080656d9 in redisplay () at xdisp.c:8276
#10 0x080d22b5 in read_char (commandflag=1, nmaps=3, maps=0xbffff0a0, 
    prev_event=405238684, used_mouse_menu=0xbffff0d8) at keyboard.c:2269
#11 0x080d8c7c in read_key_sequence (keybuf=0xbffff200, bufsize=30, 
    prompt=405238684, dont_downcase_last=0, can_return_switch_frame=1, 
    fix_current_buffer=1) at keyboard.c:8275
#12 0x080d0e7b in command_loop_1 () at keyboard.c:1437
#13 0x0812211a in internal_condition_case (bfun=0x80d0b7c <command_loop_1>, 
    handlers=405335076, hfun=0x80d07bc <cmd_error>) at eval.c:1298
#14 0x080d0a5e in command_loop_2 () at keyboard.c:1243
#15 0x08121cdb in internal_catch (tag=405296428, 
    func=0x80d0a40 <command_loop_2>, arg=405238684) at eval.c:1058
#16 0x080d09ec in command_loop () at keyboard.c:1222
#17 0x080d059e in recursive_edit_1 () at keyboard.c:948
#18 0x080d06b7 in Frecursive_edit () at keyboard.c:1004
#19 0x080cf698 in main (argc=3, argv=0xbffff7c4, envp=0xbffff7d4)
    at emacs.c:1600
#20 0x40328627 in __libc_start_main (main=0x80cea88 <main>, argc=3, 
    ubp_av=0xbffff7c4, init=0x804d8c0 <_init>, fini=0x8164474 <_fini>, 
    rtld_fini=0x4000dcd4 <_dl_fini>, stack_end=0xbffff7bc)
    at ../sysdeps/generic/libc-start.c:129

The comment before abort () in display_line says

                  /* Glyph is completely off the left margin of the
                     window.  This should not happen because of the
                     move_it_in_display_line at the start of
                     this function.  */