bug#63271: 29.0.90; broken mouse-face

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: juri@linkov.net,  luangruo@yahoo.com,  63271@debbugs.gnu.org
> Date: Tue, 09 May 2023 12:35:35 +0200
> 
> > OK, thanks.  This is still OK, so please do this with the new
> > breakpoint as described in my other email.  It would be interesting to
> > see the difference between fundamental-mode and lisp-interaction-mode
> > with that second breakpoint.
> 
> lisp-interaction-mode:
> 
> Thread 1 "emacs" hit Breakpoint 3, x_set_glyph_string_gc (
>     s=s@entry=0x7fffffffc610)
>     at /home/steve/src/emacs/emacs-29/src/xterm.c:8119
> 8119        x_set_mouse_face_gc (s);
> (gdb) print *s
> $1 = {
>   x = 16,
>   y = 51,
>   ybase = 64,
>   width = 40,
>   background_width = 633,
>   height = 17,
>   left_overhang = 0,
>   right_overhang = 0,
>   f = 0x55555611ef10,
>   w = 0x55555611f160,
>   row = 0x5555566bac90,
>   area = TEXT_AREA,
>   char2b = 0x7fffffffc5f0,
>   nchars = 5,
>   hl = DRAW_MOUSE_FACE,
>   face = 0x5555568e1310,
>   font = 0x55555603c258,
>   cmp = 0x0,
>   cmp_id = 0,
>   cmp_from = 0,
>   cmp_to = 0,
>   extends_to_end_of_line_p = true,
>   background_filled_p = false,
>   font_not_found_p = false,
>   stippled_p = false,
>   for_overlaps = 0,
>   padding_p = false,
>   gc = 0x0,
>   first_glyph = 0x55555626a030,
>   img = 0x0,
>   xwidget = 0x0,
>   slice = {
>     x = 0,
>     y = 0,
>     width = 0,
>     height = 0
>   },
>   clip_head = 0x0,
>   clip_tail = 0x0,
>   clip = {{
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }, {
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }},
>   num_clips = 0,
>   underline_position = 0,
>   underline_thickness = 0,
>   next = 0x0,
>   prev = 0x0
> }
> (gdb) print s->first_glyph - s->row->glyphs[1]
> $2 = 1
> (gdb) continue
> Continuing.
> 
> Thread 1 "emacs" hit Breakpoint 3, x_set_glyph_string_gc (
>     s=s@entry=0x7fffffffc610)
>     at /home/steve/src/emacs/emacs-29/src/xterm.c:8119
> 8119        x_set_mouse_face_gc (s);
> (gdb) print *s
> $3 = {
>   x = 16,
>   y = 51,
>   ybase = 64,
>   width = 40,
>   background_width = 633,
>   height = 17,
>   left_overhang = 0,
>   right_overhang = 0,
>   f = 0x55555611ef10,
>   w = 0x55555611f160,
>   row = 0x5555566bac90,
>   area = TEXT_AREA,
>   char2b = 0x7fffffffc5f0,
>   nchars = 5,
>   hl = DRAW_MOUSE_FACE,
>   face = 0x5555568e1310,
>   font = 0x55555603c258,
>   cmp = 0x0,
>   cmp_id = 0,
>   cmp_from = 0,
>   cmp_to = 0,
>   extends_to_end_of_line_p = true,
>   background_filled_p = false,
>   font_not_found_p = false,
>   stippled_p = false,
>   for_overlaps = 0,
>   padding_p = false,
>   gc = 0x0,
>   first_glyph = 0x55555626a030,
>   img = 0x0,
>   xwidget = 0x0,
>   slice = {
>     x = 0,
>     y = 0,
>     width = 0,
>     height = 0
>   },
>   clip_head = 0x0,
>   clip_tail = 0x0,
>   clip = {{
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }, {
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }},
>   num_clips = 0,
>   underline_position = 0,
>   underline_thickness = 0,
>   next = 0x0,
>   prev = 0x0
> }
> (gdb) print s->first_glyph - s->row->glyphs[1]
> $4 = 1
> (gdb) continue
> Continuing.
> 
> Thread 1 "emacs" hit Breakpoint 3, x_set_glyph_string_gc (
>     s=s@entry=0x7fffffffc740)
>     at /home/steve/src/emacs/emacs-29/src/xterm.c:8119
> 8119        x_set_mouse_face_gc (s);
> (gdb) print *s
> $5 = {
>   x = 16,
>   y = 51,
>   ybase = 64,
>   width = 40,
>   background_width = 633,
>   height = 17,
>   left_overhang = 0,
>   right_overhang = 0,
>   f = 0x55555611ef10,
>   w = 0x55555611f160,
>   row = 0x5555566bac90,
>   area = TEXT_AREA,
>   char2b = 0x7fffffffc720,
>   nchars = 5,
>   hl = DRAW_MOUSE_FACE,
>   face = 0x5555568e1310,
>   font = 0x55555603c258,
>   cmp = 0x0,
>   cmp_id = 0,
>   cmp_from = 0,
>   cmp_to = 0,
>   extends_to_end_of_line_p = true,
>   background_filled_p = false,
>   font_not_found_p = false,
>   stippled_p = false,
>   for_overlaps = 0,
>   padding_p = false,
>   gc = 0x0,
>   first_glyph = 0x55555626a030,
>   img = 0x0,
>   xwidget = 0x0,
>   slice = {
>     x = 0,
>     y = 0,
>     width = 0,
>     height = 0
>   },
>   clip_head = 0x0,
>   clip_tail = 0x0,
>   clip = {{
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }, {
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }},
>   num_clips = 0,
>   underline_position = 0,
>   underline_thickness = 0,
>   next = 0x0,
>   prev = 0x0
> }
> (gdb) print s->first_glyph - s->row->glyphs[1]
> $6 = 1
> 
> ============================================
> fundamental-mode:
> 
> Thread 1 "emacs" hit Breakpoint 3, x_set_glyph_string_gc (
>     s=s@entry=0x7fffffffc610)
>     at /home/steve/src/emacs/emacs-29/src/xterm.c:8119
> 8119        x_set_mouse_face_gc (s);
> (gdb) print *s
> $1 = {
>   x = 16,
>   y = 0,
>   ybase = 13,
>   width = 38,
>   background_width = 38,
>   height = 17,
>   left_overhang = 1,
>   right_overhang = 0,
>   f = 0x5555560f8190,
>   w = 0x5555560f83e0,
>   row = 0x5555566c4920,
>   area = TEXT_AREA,
>   char2b = 0x7fffffffc5f0,
>   nchars = 4,
>   hl = DRAW_MOUSE_FACE,
>   face = 0x5555561e69d0,
>   font = 0x5555565ece88,
>   cmp = 0x0,
>   cmp_id = 0,
>   cmp_from = 0,
>   cmp_to = 0,
>   extends_to_end_of_line_p = false,
>   background_filled_p = true,
>   font_not_found_p = false,
>   stippled_p = false,
>   for_overlaps = 0,
>   padding_p = false,
>   gc = 0x55555681ba10,
>   first_glyph = 0x5555565c17e0,
>   img = 0x0,
>   xwidget = 0x0,
>   slice = {
>     x = 0,
>     y = 0,
>     width = 0,
>     height = 0
>   },
>   clip_head = 0x7fffffffc610,
>   clip_tail = 0x0,
>   clip = {{
>       x = 8,
>       y = 0,
>       width = 8,
>       height = 17
>     }, {
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }},
>   num_clips = 0,
>   underline_position = 0,
>   underline_thickness = 0,
>   next = 0x7fffffffc500,
>   prev = 0x7fffffffc400
> }
> (gdb) print s->first_glyph - s->row->glyphs[1]
> $2 = 1
> (gdb) continue
> Continuing.
> 
> Thread 1 "emacs" hit Breakpoint 3, x_set_glyph_string_gc (
>     s=s@entry=0x7fffffffc500)
>     at /home/steve/src/emacs/emacs-29/src/xterm.c:8119
> 8119        x_set_mouse_face_gc (s);
> (gdb) print *s
> $3 = {
>   x = 54,
>   y = 0,
>   ybase = 13,
>   width = 8,
>   background_width = 595,
>   height = 17,
>   left_overhang = 0,
>   right_overhang = 0,
>   f = 0x5555560f8190,
>   w = 0x5555560f83e0,
>   row = 0x5555566c4920,
>   area = TEXT_AREA,
>   char2b = 0x7fffffffc4f0,
>   nchars = 1,
>   hl = DRAW_MOUSE_FACE,
>   face = 0x5555561e69d0,
>   font = 0x55555615b778,
>   cmp = 0x0,
>   cmp_id = 0,
>   cmp_from = 0,
>   cmp_to = 0,
>   extends_to_end_of_line_p = true,
>   background_filled_p = false,
>   font_not_found_p = false,
>   stippled_p = false,
>   for_overlaps = 0,
>   padding_p = false,
>   gc = 0x0,
>   first_glyph = 0x5555565c18a0,
>   img = 0x0,
>   xwidget = 0x0,
>   slice = {
>     x = 0,
>     y = 0,
>     width = 0,
>     height = 0
>   },
>   clip_head = 0x7fffffffc610,
>   clip_tail = 0x0,
>   clip = {{
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }, {
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }},
>   num_clips = 0,
>   underline_position = 0,
>   underline_thickness = 0,
>   next = 0x0,
>   prev = 0x7fffffffc610
> }
> (gdb) print s->first_glyph - s->row->glyphs[1]
> $4 = 5
> (gdb) continue
> Continuing.
> 
> Thread 1 "emacs" hit Breakpoint 3, x_set_glyph_string_gc (
>     s=s@entry=0x7fffffffc740)
>     at /home/steve/src/emacs/emacs-29/src/xterm.c:8119
> 8119        x_set_mouse_face_gc (s);
> (gdb) print *s
> $5 = {
>   x = 16,
>   y = 0,
>   ybase = 13,
>   width = 38,
>   background_width = 38,
>   height = 17,
>   left_overhang = 1,
>   right_overhang = 0,
>   f = 0x5555560f8190,
>   w = 0x5555560f83e0,
>   row = 0x5555566c4920,
>   area = TEXT_AREA,
>   char2b = 0x7fffffffc720,
>   nchars = 4,
>   hl = DRAW_MOUSE_FACE,
>   face = 0x5555561e69d0,
>   font = 0x5555565ece88,
>   cmp = 0x0,
>   cmp_id = 0,
>   cmp_from = 0,
>   cmp_to = 0,
>   extends_to_end_of_line_p = false,
>   background_filled_p = true,
>   font_not_found_p = false,
>   stippled_p = false,
>   for_overlaps = 0,
>   padding_p = false,
>   gc = 0x55555681ba10,
>   first_glyph = 0x5555565c17e0,
>   img = 0x0,
>   xwidget = 0x0,
>   slice = {
>     x = 0,
>     y = 0,
>     width = 0,
>     height = 0
>   },
>   clip_head = 0x7fffffffc740,
>   clip_tail = 0x0,
>   clip = {{
>       x = 8,
>       y = 0,
>       width = 8,
>       height = 17
>     }, {
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }},
>   num_clips = 0,
>   underline_position = 0,
>   underline_thickness = 0,
>   next = 0x7fffffffc630,
>   prev = 0x7fffffffc530
> }
> (gdb) print s->first_glyph - s->row->glyphs[1]
> $6 = 1
> (gdb) continue
> Continuing.
> 
> Thread 1 "emacs" hit Breakpoint 3, x_set_glyph_string_gc (
>     s=s@entry=0x7fffffffc630)
>     at /home/steve/src/emacs/emacs-29/src/xterm.c:8119
> 8119        x_set_mouse_face_gc (s);
> (gdb) print *s
> $7 = {
>   x = 54,
>   y = 0,
>   ybase = 13,
>   width = 8,
>   background_width = 595,
>   height = 17,
>   left_overhang = 0,
>   right_overhang = 0,
>   f = 0x5555560f8190,
>   w = 0x5555560f83e0,
>   row = 0x5555566c4920,
>   area = TEXT_AREA,
>   char2b = 0x7fffffffc620,
>   nchars = 1,
>   hl = DRAW_MOUSE_FACE,
>   face = 0x5555561e69d0,
>   font = 0x55555615b778,
>   cmp = 0x0,
>   cmp_id = 0,
>   cmp_from = 0,
>   cmp_to = 0,
>   extends_to_end_of_line_p = true,
>   background_filled_p = false,
>   font_not_found_p = false,
>   stippled_p = false,
>   for_overlaps = 0,
>   padding_p = false,
>   gc = 0x0,
>   first_glyph = 0x5555565c18a0,
>   img = 0x0,
>   xwidget = 0x0,
>   slice = {
>     x = 0,
>     y = 0,
>     width = 0,
>     height = 0
>   },
>   clip_head = 0x7fffffffc740,
>   clip_tail = 0x0,
>   clip = {{
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }, {
>       x = 0,
>       y = 0,
>       width = 0,
>       height = 0
>     }},
>   num_clips = 0,
>   underline_position = 0,
>   underline_thickness = 0,
>   next = 0x0,
>   prev = 0x7fffffffc740
> }
> (gdb) print s->first_glyph - s->row->glyphs[1]
> $8 = 5

This looks OK to me: it says we display 4 characters in one face and 1
more in another.  Which agrees with pgrow and with what I understand
should happen here: the 4 characters T O D O are displayed using the
font of the variable-pitch face, and the blank space after it is
displayed using the default face.

What do you see on the screen in this case?  Please describe the
visual appearance of each character in the case of fundamental-mode,
and perhaps also show a screenshot of the window as it is displayed
when the mouse-highlight becomes visible during this scenario.

Thanks.