[BUG] org-set-tags-command hangs indefinitely in some indirect buffers

[Adam Beckmeyer]

Hi everyone,

In some of my files, org-set-tags-command hangs indefinitely when invoked in an 
indirect buffer. Attached is an example file where you can see the behavior:

1. Open this file in org-mode.
2. Invoke org-tree-to-indirect-buffer in the "Hello World" heading
3. Invoke org-set-tags-command in the new indirect buffer.

I noticed this problem on git master but bisected and found the bug was 
introduced by: 
https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=2f7b35ac89470f17937f5c20524c38db103aaa4c

Here's a backtrace when C-g in the middle of the hanging `org-set-tags-command`:

Debugger entered--Lisp error: (quit)
org-element-headline-parser(990890 t)
#f(compiled-function (limit &optional granularity mode structure) "Parse the 
element starting at point.\n\nReturn value is a list like (TYPE PROPS) where 
TYPE is the type\nof the element and PROPS a plist of properties associated to 
the\nelement.\n\nPossible types are defined in 
`org-element-all-elements'.\n\nLIMIT bounds the search.\n\nOptional argument 
GRANULARITY determines the depth of the\nrecursion. Allowed values are 
`headline', `greater-element',\n`element', `object' or nil. When it is broader 
than `object' (or\nnil), secondary values will not be parsed, since they 
only\ncontain objects.\n\nOptional argument MODE, when non-nil, can be 
either\n`first-section', `item', `node-property', 
`planning',\n`property-drawer', `section', `table-row', or 
`top-comment'.\n\n\nIf STRUCTURE isn't provided but MODE is set to `item', it 
will be\ncomputed.\n\nThis function assumes point is always at the beginning of 
the\nelement it has to parse." #<bytecode -0xffa82cf259ad9a8>)(990890 element 
nil nil)
org-element--parse-to(990890)
org-element-at-point(990890)
org-element-cache-map(#f(compiled-function (el) #<bytecode -0x5d1d54592fb960>))
org-get-buffer-tags()
org-set-tags-command(nil)
funcall-interactively(org-set-tags-command nil)
command-execute(org-set-tags-command)


Emacs : GNU Emacs 29.1 (build 2, x86_64-unknown-linux-gnu, X toolkit, cairo 
version 1.16.0)
of 2023-08-02
Package: Org mode version 9.7-pre (release_9.6.6-412-g2f7b35 @ 
/home/adam/.emacs.d/straight/repos/org/lisp/)

Best
----

Adam Beckmeyer