bug#48740: 28.0.50; Composition text property is not always honoured

[Eli Zaretskii]

> Date: Tue, 01 Jun 2021 18:25:17 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 48740@debbugs.gnu.org
> 
> I don't know why the values of the 'composition' property become not
> 'eq'; perhaps some code does a copy-sequence or something?

Btw, looking closer at the plist of the interval after
org-agenda-redo-all, I see that it is quite a mess.  For example, the
'composition' property appears there several times, not just once.

Here's the full value of the interval's plist that I see in the
debugger in Step 6:

  (org-heading t fontified t org-todo-head #("TODO" 0 4 (face org-todo)) 
composition (0 7 [128119]) prettify-symbols-start 294 prettify-symbols-end 301 
face org-todo org-category "inbox" tags (#("SKIP" 0 4 (inherited t)) #("INBOX" 
0 5 (inherited t)) #("BOOKMARK" 0 8 (org-category "inbox" keymap (keymap 
(follow-link . mouse-face) (mouse-3 . org-find-file-at-mouse) (mouse-2 . 
org-open-at-mouse)) mouse-face highlight face (org-tag org-level-1) fontified 
t)) #("misc" 0 4 (org-category "inbox" keymap (keymap (follow-link . 
mouse-face) (mouse-3 . org-find-file-at-mouse) (mouse-2 . org-open-at-mouse)) 
mouse-face highlight face (org-tag org-level-1) fontified t))) 
org-priority-highest 65 org-priority-lowest 67 time-of-day nil duration nil 
breadcrumbs nil txt #("TODO belluzj [Github] belluzj/fantasque-sans: A font 
family with a great monospaced variant for programmers. 
:SKIP:INBOX::BOOKMARK:misc:" 0 4 (fontified t face (org-todo org-level-1) 
org-category "inbox" org-heading t) 4 108 (fontified t face org-level-1 
org-category "inbox" org-heading t) 108 110 (org-heading t) 110 114 (inherited 
t org-heading t) 114 115 (org-heading t) 115 120 (inherited t org-heading t) 
120 122 (org-heading t) 122 130 (org-category "inbox" keymap (keymap 
(follow-link . mouse-face) (mouse-3 . org-find-file-at-mouse) (mouse-2 . 
org-open-at-mouse)) mouse-face highlight face (org-tag org-level-1) fontified t 
org-heading t) 130 131 (org-heading t) 131 135 (fontified t face (org-tag 
org-level-1) mouse-face highlight keymap (keymap (follow-link . mouse-face) 
(mouse-3 . org-find-file-at-mouse) (mouse-2 . org-open-at-mouse)) org-category 
"inbox" org-heading t) 135 136 (org-heading t)) level "" time "" extra "" 
format (((org-prefix-has-time nil) (org-prefix-has-tag nil) 
(org-prefix-category-length 12) (org-prefix-has-effort nil) 
(org-prefix-has-breadcrumbs nil)) (format " %s %s" (format "%s" (if (member 
category-icon '("" nil)) "" (concat category-icon "" (get-text-property 0 
'extra-space category-icon)))) (format "%-12s" (if (member category '("" nil)) 
"" (concat category ":" (get-text-property 0 'extra-space category)))))) dotime 
t org-series-cmd nil org-redo-cmd (org-todo-list (or (and (numberp 
current-prefix-arg) current-prefix-arg) nil current-prefix-arg nil)) 
org-last-args nil org-agenda-type todo done-face org-agenda-done 
org-not-done-regexp 
"\\(DOING\\|HOLD\\|ONGOING\\|REVIEW\\|SOMEDAY\\|T\\(?:ICKLER\\|ODO\\)\\|WAITING\\)"
 org-todo-regexp 
"\\(CANCELLED\\|DO\\(?:ING\\|NE\\)\\|F\\(?:AILED\\|ROZEN\\)\\|HOLD\\|MERGED\\|ONGOING\\|REVIEW\\|SOMEDAY\\|T\\(?:ICKLER\\|ODO\\)\\|WAITING\\)"
 org-complex-heading-regexp "^\\(\\*+\\)\\(?: 
+\\(CANCELLED\\|DO\\(?:ING\\|NE\\)\\|F\\(?:AILED\\|ROZEN\\)\\|HOLD\\|MERGED\\|ONGOING\\|REVIEW\\|SOMEDAY\\|T\\(?:ICKLER\\|ODO\\)\\|WAITING\\)\\)?\\(?:
 +\\(\\[#.\\]\\)\\)?\\(?: +\\(.*?\\)\\)??\\(?:[     
]+\\(:[[:alnum:]_@#%:]+:\\)\\)?[
        ]*$" mouse-face highlight help-echo "mouse-2 or RET jump to org file 
~/data/test-org/inbox.org" org-marker #<marker (moves after insertion) at 292 
in inbox.org> org-hd-marker #<marker (moves after insertion) at 292 in 
inbox.org> priority 1001 ts-date nil type "todo" todo-state #("TODO" 0 4 
(fontified t face (org-todo org-level-1) org-category "inbox")))

And here's the value in Step 8:

  (org-series-cmd nil org-redo-cmd (org-todo-list (or (and (numberp 
current-prefix-arg) current-prefix-arg) nil current-prefix-arg nil)) 
org-last-args nil org-agenda-type todo todo-state #("ONGOING" 0 3 (fontified t 
org-todo-head #("TODO" 0 4 (face org-todo)) composition (0 7 [128119]) 
prettify-symbols-start 294 prettify-symbols-end 301 face (org-todo org-level-1) 
org-category "inbox") 3 7 (fontified t org-todo-head #("TODO" 0 4 (face 
org-todo)) composition (0 7 [128119]) prettify-symbols-start 294 
prettify-symbols-end 301 face (org-todo org-level-1) org-category "inbox")) 
type "todo" ts-date nil priority 1001 org-hd-marker #<marker (moves after 
insertion) at 292 in inbox.org> org-marker #<marker (moves after insertion) at 
292 in inbox.org> help-echo "mouse-2 or RET jump to org file 
~/data/test-org/inbox.org" mouse-face highlight org-complex-heading-regexp 
"^\\(\\*+\\)\\(?: 
+\\(CANCELLED\\|DO\\(?:ING\\|NE\\)\\|F\\(?:AILED\\|ROZEN\\)\\|HOLD\\|MERGED\\|ONGOING\\|REVIEW\\|SOMEDAY\\|T\\(?:ICKLER\\|ODO\\)\\|WAITING\\)\\)?\\(?:
 +\\(\\[#.\\]\\)\\)?\\(?: +\\(.*?\\)\\)??\\(?:[    
]+\\(:[[:alnum:]_@#%:]+:\\)\\)?[
        ]*$" org-todo-regexp 
"\\(CANCELLED\\|DO\\(?:ING\\|NE\\)\\|F\\(?:AILED\\|ROZEN\\)\\|HOLD\\|MERGED\\|ONGOING\\|REVIEW\\|SOMEDAY\\|T\\(?:ICKLER\\|ODO\\)\\|WAITING\\)"
 org-not-done-regexp 
"\\(DOING\\|HOLD\\|ONGOING\\|REVIEW\\|SOMEDAY\\|T\\(?:ICKLER\\|ODO\\)\\|WAITING\\)"
 done-face org-agenda-done dotime t format (((org-prefix-has-time nil) 
(org-prefix-has-tag nil) (org-prefix-category-length 12) (org-prefix-has-effort 
nil) (org-prefix-has-breadcrumbs nil)) (format " %s %s" (format "%s" (if 
(member category-icon '("" nil)) "" (concat category-icon "" (get-text-property 
0 'extra-space category-icon)))) (format "%-12s" (if (member category '("" 
nil)) "" (concat category ":" (get-text-property 0 'extra-space category)))))) 
extra "" time "" level " " txt #("ONGOING belluzj [Github] 
belluzj/fantasque-sans: A font family with a great monospaced variant for 
programmers. :SKIP:INBOX::BOOKMARK:misc:" 0 3 (fontified t org-todo-head 
#("TODO" 0 4 (face org-todo)) composition (0 7 [128119]) prettify-symbols-start 
294 prettify-symbols-end 301 face (org-todo org-level-1) org-category "inbox" 
org-heading t) 3 7 (fontified t org-todo-head #("TODO" 0 4 (face org-todo)) 
composition (0 7 [128119]) prettify-symbols-start 294 prettify-symbols-end 301 
face (org-todo org-level-1) org-category "inbox" org-heading t) 7 8 (fontified 
t org-todo-head #("TODO" 0 4 (face org-todo)) face org-level-1 org-category 
"inbox" org-heading t) 8 111 (fontified t org-category "inbox" org-todo-head 
#("TODO" 0 4 (face org-todo)) face org-level-1 org-heading t) 111 113 
(org-heading t) 113 117 (inherited t org-heading t) 117 118 (org-heading t) 118 
123 (inherited t org-heading t) 123 125 (org-heading t) 125 133 (keymap (keymap 
(follow-link . mouse-face) (mouse-3 . org-find-file-at-mouse) (mouse-2 . 
org-open-at-mouse)) mouse-face highlight face (org-tag org-level-1) 
org-todo-head #("TODO" 0 4 (face org-todo)) org-category "inbox" fontified t 
org-heading t) 133 134 (org-heading t) 134 138 (fontified t org-category 
"inbox" org-todo-head #("TODO" 0 4 (face org-todo)) face (org-tag org-level-1) 
mouse-face highlight keymap (keymap (follow-link . mouse-face) (mouse-3 . 
org-find-file-at-mouse) (mouse-2 . org-open-at-mouse)) org-heading t) 138 139 
(org-heading t)) breadcrumbs nil duration nil time-of-day nil 
org-priority-lowest 67 org-priority-highest 65 tags (#("SKIP" 0 4 (inherited 
t)) #("INBOX" 0 5 (inherited t)) #("BOOKMARK" 0 8 (keymap (keymap (follow-link 
. mouse-face) (mouse-3 . org-find-file-at-mouse) (mouse-2 . org-open-at-mouse)) 
mouse-face highlight face (org-tag org-level-1) org-todo-head #("TODO" 0 4 
(face org-todo)) org-category "inbox" fontified t)) #("misc" 0 4 (keymap 
(keymap (follow-link . mouse-face) (mouse-3 . org-find-file-at-mouse) (mouse-2 
. org-open-at-mouse)) mouse-face highlight face (org-tag org-level-1) 
org-todo-head #("TODO" 0 4 (face org-todo)) org-category "inbox" fontified t))) 
fontified t org-todo-head #("TODO" 0 4 (face org-todo)) composition (0 7 
[128119]) prettify-symbols-start 294 prettify-symbols-end 301 face org-todo 
org-category "inbox" org-heading t)

As you see, the 'composition' property appears only once in Step 6,
but 5 times in Step 8.  This is probably part of the problem, or at
least its symptom.