Yes, I have reported it in https://github.com/jdtsmith/outli/issues/17 and the developer
recommended me to file this bug report. This is what he said:

> This seems to be a new conflict with Emacs 31, and potentially a problem with treesit-outline.
> Can you please file an Emacs bug report and link it here?

Date: Mon, 18 Nov 2024 10:59:00 +0800
From: Taka Obsid <liaotx2@gmail.com>

Hi, I'm using `java-ts-mode' and https://github.com/jdtsmith/outli.

While I tried to `revert-buffer' in a java file, it reports
`outline-map-region: Wrong type argument: number-or-marker-p, nil'.

The backtrace is:

```bt
Debugger entered--Lisp error: (wrong-type-argument number-or-marker-p nil)
#f(compiled-function () #<bytecode -0x1964e0de811a96ab>)()
outline-map-region(#f(compiled-function () #<bytecode 
-0x1964e0de811a96ab>) 1 31382)
outline--hidden-headings-paths()
outline-revert-buffer-restore-visibility()
#f(compiled-function (f) #<bytecode 
0x6badcbe8273644b>)(outline-revert-buffer-restore-visibility)
run-hook-wrapped(#f(compiled-function (f) #<bytecode 0x6badcbe8273644b>) 
outline-revert-buffer-restore-visibility)
revert-buffer(t)
funcall-interactively(revert-buffer t)
call-interactively(revert-buffer record nil)
command-execute(revert-buffer record)
execute-extended-command(nil "revert-buffer" "rev")
funcall-interactively(execute-extended-command nil "revert-buffer" "rev")
call-interactively(execute-extended-command nil nil)
command-execute(execute-extended-command)
```

To repreduce it:

1. start Emacs with `java-ts-mode' and `outli' installed;

2. go to a java file;

3. `M-x outli-mode';

4. `M-x revert-buffer'.

The `outline-search-function' is `#'treesit-outline-search' and while I
set it to `nil', I can successfully revert the buffer.


```
emacs -q --eval "(progn
(add-to-list 'load-path \"/path/to/java-ts-mode/\")
(add-to-list 'load-path \"/path/to/outli/\")
(require 'java-ts-mode)
(require 'outli))"
```

Thanks, this seems to be a problem in the outli package?  Because the
error is signaled by one of its functions (a hook it places on
revert-buffer-function, I guess?).

Did you report this to the developer of outli?  If not, I suggest to
report it there first.