bug#28710: 27.0.50; eassert failure in maybe_produce_line_number

[Alex]

Eli Zaretskii <eliz@gnu.org> writes:

> OK, so we need to understand the path the code takes after try_window
> returns the value 1.  This means, after typing "finish" 3 times, type
> "next", then continue pressing RET until redisplay_window returns.  I
> need to see the path through the code until we exit redisplay_window
> to understand where to put the missing call to clear_glyph_matrix.

Thread 1 "emacs" hit Hardware watchpoint 2: -location 
$1->desired_matrix->rows->enabled_p

Old value = false
New value = true
prepare_desired_row (w=0x15cac30 <bss_sbrk_buffer+8062480>, row=0x4827bc0, 
mode_line_p=false) at dispnew.c:1076
1076          row->reversed_p = rp;
(gdb) b xdisp.c:17039
Breakpoint 3 at 0x474844: file xdisp.c, line 17039.
(gdb) commands
Type commands for breakpoint(s) 3, one per line.
End with a line saying just "end".
>p w->desired_matrix->rows->enabled_p
>end
(gdb) finish
Run till exit from #0  prepare_desired_row (
    w=0x15cac30 <bss_sbrk_buffer+8062480>, row=0x4827bc0, mode_line_p=false)
    at dispnew.c:1076
display_line (it=0x7ffd11e08a20, cursor_vpos=26) at xdisp.c:21208
21208     row->y = it->current_y;
(gdb) finish
Run till exit from #0  display_line (it=0x7ffd11e08a20, cursor_vpos=26)
    at xdisp.c:21208
0x0000000000477380 in try_window (window=..., pos=..., flags=1)
    at xdisp.c:17592
17592         if (display_line (&it, cursor_vpos))
Value returned is $2 = true
(gdb) finish
Run till exit from #0  0x0000000000477380 in try_window (window=..., pos=..., 
    flags=1) at xdisp.c:17592
0x0000000000474866 in redisplay_window (window=..., just_this_one_p=false)
    at xdisp.c:17039
17039             if (try_window (window, startp, TRY_WINDOW_CHECK_MARGINS) < 0)
Value returned is $3 = 1
(gdb) n
17046         if (f->fonts_changed)
(gdb) 
17049         if (w->cursor.vpos >= 0)
(gdb) 
17051             if (!just_this_one_p
(gdb) 
17055               w->base_line_number = 0;
(gdb) 
17057             if (!cursor_row_fully_visible_p (w, true, false))
(gdb) 
17064               goto done;
(gdb) 
17393     SET_TEXT_POS_FROM_MARKER (startp, w->start);
(gdb) 
17394     w->start_at_line_beg = (CHARPOS (startp) == BEGV
(gdb) 
17395                             || FETCH_BYTE (BYTEPOS (startp) - 1) == '\n');
(gdb) 
17394     w->start_at_line_beg = (CHARPOS (startp) == BEGV
(gdb) 
17398     if ((update_mode_line
(gdb) 
17412         && (window_wants_mode_line (w)
(gdb) 

17416         display_mode_lines (w);
(gdb) 
17420         if (window_wants_mode_line (w)
(gdb) 
17421             && CURRENT_MODE_LINE_HEIGHT (w) != DESIRED_MODE_LINE_HEIGHT 
(w))
(gdb) 
17431         if (window_wants_header_line (w)
(gdb) 
17440         if (f->fonts_changed)
(gdb) 
17444     if (!line_number_displayed && w->base_line_pos != -1)
(gdb) 
17450    finish_menu_bars:
(gdb) 
17454     if (update_mode_line
(gdb) 
17455         && EQ (FRAME_SELECTED_WINDOW (f), window))
(gdb) 
17459         if (FRAME_WINDOW_P (f))
(gdb) 
17463             redisplay_menu_p = FRAME_EXTERNAL_MENU_BAR (f);
(gdb) 
17471         if (redisplay_menu_p)
(gdb) 
17472           display_menu_bar (w);
(gdb) 
17475         if (FRAME_WINDOW_P (f))
(gdb) 
17478             if (FRAME_EXTERNAL_TOOL_BAR (f))
(gdb) 
17479               redisplay_tool_bar (f);
(gdb) 
17488         x_consider_frame_title (w->frame);
(gdb) 
17493     if (FRAME_WINDOW_P (f)
(gdb) 
17496                                       || w->pseudo_window_p)))
(gdb) 
17495                                       || (!used_current_matrix_p && 
!overlay_arrow_seen)
(gdb) 
17494         && update_window_fringes (w, (just_this_one_p
(gdb) 
17511     if (WINDOW_BOTTOM_DIVIDER_WIDTH (w))
(gdb) 
17519    need_larger_matrices:
(gdb) 
17523      if (WINDOW_HAS_VERTICAL_SCROLL_BAR (w) || 
WINDOW_HAS_HORIZONTAL_SCROLL_BAR (w))
(gdb) 
17525         if (WINDOW_HAS_VERTICAL_SCROLL_BAR (w))
(gdb) 
17527           set_vertical_scroll_bar (w);
(gdb) 
17529         if (WINDOW_HAS_HORIZONTAL_SCROLL_BAR (w))
(gdb) 
17535         if (FRAME_TERMINAL (f)->redeem_scroll_bar_hook)
(gdb) 
17536           (*FRAME_TERMINAL (f)->redeem_scroll_bar_hook) (w);
(gdb) 

17542     if (CHARPOS (opoint) < BEGV)
(gdb) 
17544     else if (CHARPOS (opoint) > ZV)
(gdb) 
17547       TEMP_SET_PT_BOTH (CHARPOS (opoint), BYTEPOS (opoint));
(gdb) 
17549     set_buffer_internal_1 (old);
(gdb) 
17552     if (CHARPOS (lpoint) <= ZV)
(gdb) 
17553       TEMP_SET_PT_BOTH (CHARPOS (lpoint), BYTEPOS (lpoint));
(gdb) 
17555     unbind_to (count, Qnil);
(gdb) 
17556   }
(gdb) 
redisplay_window_0 (window=...) at xdisp.c:14800
14800     return Qnil;
(gdb) 
14801   }
(gdb) 
internal_condition_case_1 (bfun=0x46cfbf <redisplay_window_0>, arg=..., 
handlers=..., hfun=0x46cf87 <redisplay_window_error>) at eval.c:1357
1357          eassert (handlerlist == c);
(gdb) 
1358          handlerlist = c->next;
(gdb) 
1359          return val;
(gdb) 
1361    }
(gdb) 
redisplay_windows (window=...) at xdisp.c:14784
14784         window = w->next;
(gdb) 
14768     while (!NILP (window))
(gdb) 
14770         struct window *w = XWINDOW (window);
(gdb) 
14772         if (WINDOWP (w->contents))
(gdb) 
14774         else if (BUFFERP (w->contents))
(gdb) 
14776             displayed_buffer = XBUFFER (w->contents);
(gdb) 
14779             internal_condition_case_1 (redisplay_window_0, window,
(gdb) 
14784         window = w->next;
(gdb) 
14768     while (!NILP (window))
(gdb) 
14786   }
(gdb) 
redisplay_internal () at xdisp.c:14275
14275                 if (!FRAME_LIVE_P (f))
(gdb) 
14280                 if (gcscrollbars && FRAME_TERMINAL 
(f)->judge_scroll_bars_hook)
(gdb) 
14281                   FRAME_TERMINAL (f)->judge_scroll_bars_hook (f);
(gdb) 
14283                 if (FRAME_VISIBLE_P (f) && !FRAME_OBSCURED_P (f))
(gdb) 
14286                     if (f->fonts_changed)
(gdb) 
14298                     if (!f->already_hscrolled_p)
(gdb) 
14300                         f->already_hscrolled_p = true;
(gdb) 
14301                         if (hscroll_retries <= MAX_HSCROLL_RETRIES
(gdb) 
14302                             && hscroll_windows (f->root_window))
(gdb) 
14320                     if (!f_redisplay_flag && f->redisplay)
(gdb) 
14321                       goto retry_frame;
(gdb) 
14256             if (FRAME_WINDOW_P (f) || FRAME_TERMCAP_P (f) || f == sf)
(gdb) 
14260                   = f->redisplay || !REDISPLAY_SOME_P ();
(gdb) 
14258                 bool gcscrollbars
(gdb) 
14261                 bool f_redisplay_flag = f->redisplay;
(gdb) 
14264                 if (gcscrollbars && FRAME_TERMINAL 
(f)->condemn_scroll_bars_hook)
(gdb) 
14265                   FRAME_TERMINAL (f)->condemn_scroll_bars_hook (f);
(gdb) 
14267                 if (FRAME_VISIBLE_P (f) && !FRAME_OBSCURED_P (f))
(gdb) 
14268                   redisplay_windows (FRAME_ROOT_WINDOW (f));
(gdb) 

Thread 1 "emacs" hit Breakpoint 3, redisplay_window (window=..., 
just_this_one_p=false) at xdisp.c:17039
17039             if (try_window (window, startp, TRY_WINDOW_CHECK_MARGINS) < 0)
$4 = true
(gdb) 

Thread 1 "emacs" received signal SIGABRT, Aborted.
raise (sig=6) at ../sysdeps/unix/sysv/linux/raise.c:51

>> Have you tried using MELPA[1] to install magit? Maybe that would
>> work.
>
> I'm not sure how will this help.  I don't want to install Magit, I
> just use it from a directory where I unzipped its snapshot.  How using
> MELPA would change that?

I'm not sure how either; MELPA was just on my mind since that's how I'm
using Magit's dependencies.