bug#24614: 25.1.50; Exception after moving mouse over over a different window

[Alain Schneble <a.s@realize.ch>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Alain Schneble <a.s@realize.ch>
>> CC: <24614@debbugs.gnu.org>
>> Date: Tue, 4 Oct 2016 19:24:34 +0200
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > What about
>> >
>> >  (gdb) p *glyph
>> >
>> 
>> (gdb) p *glyph
>> Cannot access memory at address 0x10c46fd0
>
> So this is our villain.  Now how could that happen?  I hope the GDB
> session is still alive; if it is, what do the commands below report?
>
>  (gdb) frame 11
>  (gdb) p *glyph_row
>  (gdb) p w->output_cursor
>  (gdb) p w->current_matrix->nrows
>  (gdb) p w->current_matrix->matrix_w

Fortunately, yes.  Here it is:

(gdb) frame 11
#11 display_and_set_cursor (w=w@entry=0x12af8400, on=on@entry=true, hpos=<optimized out>, vpos=<optimized out>, x=0, y=280) at xdisp.c:28496
28496	  new_cursor_type = get_window_cursor_type (w, glyph,
(gdb) p *glyph_row
$6 = {
  glyphs = {0x10c47010, 0x10c47010, 0x10c558d0, 0x10c558d0}, 
  used = {0, 1, 0, 0}, 
  hash = 32, 
  x = 0, 
  y = 280, 
  pixel_width = 7, 
  ascent = 11, 
  height = 14, 
  phys_ascent = 11, 
  phys_height = 14, 
  visible_height = 14, 
  extra_line_spacing = 0, 
  start = {
    pos = {
      charpos = 39105, 
      bytepos = 39116
    }, 
    overlay_string_index = -1, 
    string_pos = {
      charpos = -1, 
      bytepos = -1
    }, 
    dpvec_index = -1
  }, 
  end = {
    pos = {
      charpos = 39119, 
      bytepos = 39130
    }, 
    overlay_string_index = -1, 
    string_pos = {
      charpos = -1, 
      bytepos = -1
    }, 
    dpvec_index = -1
  }, 
  minpos = {
    charpos = 39105, 
    bytepos = 39116
  }, 
  maxpos = {
    charpos = 39119, 
    bytepos = 39130
  }, 
  overlay_arrow_bitmap = 0, 
  left_user_fringe_bitmap = 0, 
  right_user_fringe_bitmap = 0, 
  left_fringe_bitmap = 3, 
  right_fringe_bitmap = 0, 
  left_user_fringe_face_id = 0, 
  right_user_fringe_face_id = 0, 
  left_fringe_face_id = 0, 
  right_fringe_face_id = 0, 
  left_fringe_offset = 0, 
  right_fringe_offset = 0, 
  fringe_bitmap_periodic_p = false, 
  redraw_fringe_bitmaps_p = false, 
  enabled_p = true, 
  truncated_on_left_p = true, 
  truncated_on_right_p = false, 
  continued_p = false, 
  displays_text_p = true, 
  ends_at_zv_p = false, 
  fill_line_p = false, 
  indicate_empty_line_p = false, 
  contains_overlapping_glyphs_p = false, 
  full_width_p = false, 
  mode_line_p = false, 
  overlapped_p = false, 
  ends_in_middle_of_char_p = false, 
  starts_in_middle_of_char_p = false, 
  overlapping_p = false, 
  mouse_face_p = false, 
  ends_in_newline_from_string_p = false, 
  exact_window_width_line_p = false, 
  cursor_in_fringe_p = false, 
  ends_in_ellipsis_p = false, 
  indicate_bob_p = false, 
  indicate_top_line_p = false, 
  indicate_eob_p = false, 
  indicate_bottom_line_p = false, 
  reversed_p = false, 
  continuation_lines_width = 0, 
  clip = 0x0
}
(gdb) p w->output_cursor
$7 = {
  x = 0, 
  y = 280, 
  hpos = -1, 
  vpos = 20
}
(gdb) p w->current_matrix->nrows
$8 = 183
(gdb) p w->current_matrix->matrix_w
$9 = 931