Re: Lexbind (was: Emacs 23.3 released)

[Juanma Barranquero]

On Thu, Mar 17, 2011 at 20:24, Eli Zaretskii <el...@gnu.org> wrote:

> It would make sense to turn off bidi reordering and see if the hangs
> still happen.

Yes, it hangs with bidi turned off.

> Which means it loops inside try_scrolling.  Next step is to see where
> it loops there, and why it doesn't return.

It's looping here (in the else part, obviously):

start_display (&it, w, startp);
if (scroll_max < INT_MAX)
move_it_vertically (&it, amount_to_scroll);
else
{
/* Extra precision for users who set scroll-conservatively
to most-positive-fixnum: make sure the amount we scroll
the window start is never less than amount_to_scroll,
which was computed as distance from window bottom to
point. This matters when lines at window top and lines
below window bottom have different height. */
struct it it1 = it;
/* We use a temporary it1 because line_bottom_y can modify
its argument, if it moves one line down; see there. */
int start_y = line_bottom_y (&it1);

do {
move_it_by_lines (&it, 1, 1);
it1 = it;
} while (line_bottom_y (&it1) - start_y < amount_to_scroll);
}

In my current session, line_bottom_y (&it1) == 15, start_y == 15,
amount_to_scroll == 15, forever and ever and ever.

    Juanma

(gdb) p it
$2 = {
window = 55221765,
w = 0x34a9e00,
f = 0x343c800,
method = GET_FROM_BUFFER,
stop_charpos = 53,
prev_stop = 0,
base_level_stop = 0,
end_charpos = 53,
s = 0x0,
string_nchars = 0,
region_beg_charpos = -1,
region_end_charpos = -1,
redisplay_end_trigger_charpos = 0,
multibyte_p = 1,
header_line_p = 0,
string_from_display_prop_p = 0,
ellipsis_p = 0,
avoid_cursor_p = 0,
dp = 0x343cc00,
dpvec = 0x0,
dpend = 0x0,
dpvec_char_len = 0,
dpvec_face_id = 0,
saved_face_id = 12,
ctl_chars = {0 <repeats 16 times>},
start = {
pos = {
charpos = 1,
bytepos = 1
},
overlay_string_index = -1,
string_pos = {
charpos = -1,
bytepos = -1
},
dpvec_index = -1
},
current = {
pos = {
charpos = 53,
bytepos = 53
},
overlay_string_index = -1,
string_pos = {
charpos = -1,
bytepos = -1
},
dpvec_index = -1
},
n_overlay_strings = 0,
overlay_strings_charpos = 53,
overlay_strings = {84671601, 0 <repeats 15 times>},
string_overlays = {81053227, 0 <repeats 15 times>},
string = 52250650,
from_overlay = 0,
stack = {{
string = 52250650,
string_nchars = 0,
end_charpos = 53,
stop_charpos = 2,
prev_stop = 0,
base_level_stop = 0,
cmp_it = {
stop_pos = 50,
id = -1,
ch = -2,
rule_idx = 0,
lookback = 0,
nglyphs = 0,
reversed_p = 0,
charpos = 0,
nchars = 0,
nbytes = 0,
from = 0,
to = 0,
width = 0
},
face_id = 12,
u = {
image = {
object = 0,
slice = {
x = 0,
y = 0,
width = 0,
height = 0
},
image_id = 0
},
comp = {
object = 0
},
stretch = {
object = 0
}
},
position = {
charpos = 1,
bytepos = 1
},
current = {
pos = {
charpos = 1,
bytepos = 1
},
overlay_string_index = 0,
string_pos = {
charpos = -1,
bytepos = -1
},
dpvec_index = -1
},
from_overlay = 0,
area = TEXT_AREA,
method = GET_FROM_BUFFER,
multibyte_p = 1,
string_from_display_prop_p = 0,
display_ellipsis_p = 0,
avoid_cursor_p = 0,
line_wrap = WINDOW_WRAP,
voffset = 0,
space_width = 52250650,
font_height = 52250650
}, {
string = 0,
string_nchars = 0,
end_charpos = 0,
stop_charpos = 0,
prev_stop = 0,
base_level_stop = 0,
cmp_it = {
stop_pos = 0,
id = 0,
ch = 0,
rule_idx = 0,
lookback = 0,
nglyphs = 0,
reversed_p = 0,
charpos = 0,
nchars = 0,
nbytes = 0,
from = 0,
to = 0,
width = 0
},
face_id = 0,
u = {
image = {
object = 0,
slice = {
x = 0,
y = 0,
width = 0,
height = 0
},
image_id = 0
},
comp = {
object = 0
},
stretch = {
object = 0
}
},
position = {
charpos = 0,
bytepos = 0
},
current = {
pos = {
charpos = 0,
bytepos = 0
},
overlay_string_index = 0,
string_pos = {
charpos = 0,
bytepos = 0
},
dpvec_index = 0
},
from_overlay = 0,
area = LEFT_MARGIN_AREA,
method = GET_FROM_BUFFER,
multibyte_p = 0,
string_from_display_prop_p = 0,
display_ellipsis_p = 0,
avoid_cursor_p = 0,
line_wrap = TRUNCATE,
voffset = 0,
space_width = 0,
font_height = 0
}, {
string = 0,
string_nchars = 0,
end_charpos = 0,
stop_charpos = 0,
prev_stop = 0,
base_level_stop = 0,
cmp_it = {
stop_pos = 0,
id = 0,
ch = 0,
rule_idx = 0,
lookback = 0,
nglyphs = 0,
reversed_p = 0,
charpos = 0,
nchars = 0,
nbytes = 0,
from = 0,
to = 0,
width = 0
},
face_id = 0,
u = {
image = {
object = 0,
slice = {
x = 0,
y = 0,
width = 0,
height = 0
},
image_id = 0
},
comp = {
object = 0
},
stretch = {
object = 0
}
},
position = {
charpos = 0,
bytepos = 0
},
current = {
pos = {
charpos = 0,
bytepos = 0
},
overlay_string_index = 0,
string_pos = {
charpos = 0,
bytepos = 0
},
dpvec_index = 0
},
from_overlay = 0,
area = LEFT_MARGIN_AREA,
method = GET_FROM_BUFFER,
multibyte_p = 0,
string_from_display_prop_p = 0,
display_ellipsis_p = 0,
avoid_cursor_p = 0,
line_wrap = TRUNCATE,
voffset = 0,
space_width = 0,
font_height = 0
}, {
string = 0,
string_nchars = 0,
end_charpos = 0,
stop_charpos = 0,
prev_stop = 0,
base_level_stop = 0,
cmp_it = {
stop_pos = 0,
id = 0,
ch = 0,
rule_idx = 0,
lookback = 0,
nglyphs = 0,
reversed_p = 0,
charpos = 0,
nchars = 0,
nbytes = 0,
from = 0,
to = 0,
width = 0
},
face_id = 0,
u = {
image = {
object = 0,
slice = {
x = 0,
y = 0,
width = 0,
height = 0
},
image_id = 0
},
comp = {
object = 0
},
stretch = {
object = 0
}
},
position = {
charpos = 0,
bytepos = 0
},
current = {
pos = {
charpos = 0,
bytepos = 0
},
overlay_string_index = 0,
string_pos = {
charpos = 0,
bytepos = 0
},
dpvec_index = 0
},
from_overlay = 0,
area = LEFT_MARGIN_AREA,
method = GET_FROM_BUFFER,
multibyte_p = 0,
string_from_display_prop_p = 0,
display_ellipsis_p = 0,
avoid_cursor_p = 0,
line_wrap = TRUNCATE,
voffset = 0,
space_width = 0,
font_height = 0
}, {
string = 0,
string_nchars = 0,
end_charpos = 0,
stop_charpos = 0,
prev_stop = 0,
base_level_stop = 0,
cmp_it = {
stop_pos = 0,
id = 0,
ch = 0,
rule_idx = 0,
lookback = 0,
nglyphs = 0,
reversed_p = 0,
charpos = 0,
nchars = 0,
nbytes = 0,
from = 0,
to = 0,
width = 0
},
face_id = 0,
u = {
image = {
object = 0,
slice = {
x = 0,
y = 0,
width = 0,
height = 0
},
image_id = 0
},
comp = {
object = 0
},
stretch = {
object = 0
}
},
position = {
charpos = 0,
bytepos = 0
},
current = {
pos = {
charpos = 0,
bytepos = 0
},
overlay_string_index = 0,
string_pos = {
charpos = 0,
bytepos = 0
},
dpvec_index = 0
},
from_overlay = 0,
area = LEFT_MARGIN_AREA,
method = GET_FROM_BUFFER,
multibyte_p = 0,
string_from_display_prop_p = 0,
display_ellipsis_p = 0,
avoid_cursor_p = 0,
line_wrap = TRUNCATE,
voffset = 0,
space_width = 0,
font_height = 0
}},
sp = 0,
selective = 0,
what = IT_EOB,
face_id = 0,
selective_display_ellipsis_p = 1,
ctl_arrow_p = 1,
face_box_p = 0,
start_of_box_run_p = 0,
end_of_box_run_p = 0,
overlay_strings_at_end_processed_p = 1,
ignore_overlay_strings_at_pos_p = 0,
glyph_not_available_p = 0,
starts_in_middle_of_char_p = 0,
face_before_selective_p = 0,
constrain_row_ascent_descent_p = 0,
line_wrap = WINDOW_WRAP,
base_face_id = 0,
c = 101,
len = 1,
cmp_it = {
stop_pos = 50,
id = -1,
ch = -2,
rule_idx = 0,
lookback = 0,
nglyphs = 0,
reversed_p = 0,
charpos = 0,
nchars = 0,
nbytes = 0,
from = 0,
to = 0,
width = 0
},
char_to_display = 101,
glyphless_method = GLYPHLESS_DISPLAY_THIN_SPACE,
image_id = 0,
slice = {
x = 52250650,
y = 52250650,
width = 52250650,
height = 52250650
},
space_width = 52250650,
voffset = 0,
tab_width = 8,
font_height = 52250650,
object = 80814597,
position = {
charpos = 53,
bytepos = 53
},
truncation_pixel_width = 0,
continuation_pixel_width = 0,
first_visible_x = 0,
last_visible_x = 928,
last_visible_y = 15,
extra_line_spacing = 0,
max_extra_line_spacing = 0,
override_ascent = -1,
override_descent = 0,
override_boff = 0,
glyph_row = 0x4ce0800,
area = TEXT_AREA,
nglyphs = 1,
pixel_width = 8,
ascent = 12,
descent = 3,
max_ascent = 12,
max_descent = 3,
phys_ascent = 12,
phys_descent = 3,
max_phys_ascent = 12,
max_phys_descent = 3,
current_x = 432,
continuation_lines_width = 0,
eol_pos = {
charpos = 0,
bytepos = 0
},
current_y = 0,
first_vpos = 0,
vpos = 0,
hpos = 54,
left_user_fringe_bitmap = 0,
right_user_fringe_bitmap = 0,
left_user_fringe_face_id = 0,
right_user_fringe_face_id = 0,
bidi_p = 0,
bidi_it = {
bytepos = 0,
charpos = 0,
ch = 0,
ch_len = 0,
type = UNKNOWN_BT,
type_after_w1 = UNKNOWN_BT,
orig_type = UNKNOWN_BT,
resolved_level = 0,
invalid_levels = 0,
invalid_rl_levels = 0,
prev_was_pdf = 0,
prev = {
bytepos = 0,
charpos = 0,
type = UNKNOWN_BT,
type_after_w1 = UNKNOWN_BT,
orig_type = UNKNOWN_BT
},
last_strong = {
bytepos = 0,
charpos = 0,
type = UNKNOWN_BT,
type_after_w1 = UNKNOWN_BT,
orig_type = UNKNOWN_BT
},
next_for_neutral = {
bytepos = 0,
charpos = 0,
type = UNKNOWN_BT,
type_after_w1 = UNKNOWN_BT,
orig_type = UNKNOWN_BT
},
prev_for_neutral = {
bytepos = 0,
charpos = 0,
type = UNKNOWN_BT,
type_after_w1 = UNKNOWN_BT,
orig_type = UNKNOWN_BT
},
next_for_ws = {
bytepos = 0,
charpos = 0,
type = UNKNOWN_BT,
type_after_w1 = UNKNOWN_BT,
orig_type = UNKNOWN_BT
},
next_en_pos = 0,
ignore_bn_limit = 0,
sor = NEUTRAL_DIR,
scan_dir = 0,
stack_idx = 0,
level_stack = {{
level = 0,
override = NEUTRAL_DIR
} <repeats 64 times>},
first_elt = 0,
paragraph_dir = NEUTRAL_DIR,
new_paragraph = 0,
separator_limit = 0
},
paragraph_embedding = NEUTRAL_DIR
}
(gdb) n
13129 it1 = it;
(gdb) n
13130 } while (line_bottom_y (&it1) - start_y < amount_to_scroll);
(gdb) p start_y
$3 = 15
(gdb) p amount_to_scroll
$4 = 15
(gdb) p line_bottom_y (&it1)
$5 = 15
(gdb) n
13128 move_it_by_lines (&it, 1, 1);
(gdb)
13129 it1 = it;
(gdb)
13130 } while (line_bottom_y (&it1) - start_y < amount_to_scroll);
(gdb)
13128 move_it_by_lines (&it, 1, 1);
(gdb)
13129 it1 = it;
(gdb)
13130 } while (line_bottom_y (&it1) - start_y < amount_to_scroll);
(gdb) p line_bottom_y (&it1)
$6 = 15
(gdb)

[Eli Zaretskii]

> From: Juanma Barranquero <lek...@gmail.com>
> Date: Sat, 19 Mar 2011 01:54:43 +0100
> Cc: mon...@iro.umontreal.ca, emacs...@gnu.org

>
> It's looping here (in the else part, obviously):
>
> start_display (&it, w, startp);
> if (scroll_max < INT_MAX)
> move_it_vertically (&it, amount_to_scroll);
> else
> {
> /* Extra precision for users who set scroll-conservatively
> to most-positive-fixnum: make sure the amount we scroll
> the window start is never less than amount_to_scroll,
> which was computed as distance from window bottom to
> point. This matters when lines at window top and lines
> below window bottom have different height. */
> struct it it1 = it;
> /* We use a temporary it1 because line_bottom_y can modify
> its argument, if it moves one line down; see there. */
> int start_y = line_bottom_y (&it1);
>
> do {
> move_it_by_lines (&it, 1, 1);
> it1 = it;
> } while (line_bottom_y (&it1) - start_y < amount_to_scroll);
> }
>
> In my current session, line_bottom_y (&it1) == 15, start_y == 15,
> amount_to_scroll == 15, forever and ever and ever.

So you are saying that the do-while loop is never exited, is that it?
If so, could you step inside move_it_by_lines and see why it doesn't
(move, that is)? It is supposed to move one line down.

Also, can you show the text through which this loop is supposed to
move down? If that text is displayed on the screen, are there some
unusual features it uses, like invisible text or continuation lines?