Re: commit 5ea0228 has problem opening big org-mode file

[Nick Dokos <ndokos@gmail.com>]

Nick Dokos <ndokos@gmail.com> writes:

> York Zhao <gtdplatform@gmail.com> writes:
>
>> Hi List,
>>
>> I have an org-mode file that is 3230004 bytes in size. With commit "92f30ae" it
>> can be opened without any problem. However, with commit "5ea0228" the same file
>> could not be opened properly.
>>
>> What I did was: I opened Dired buffer, select the file, press enter, nothing
>> happened and Emacs locks up, hit C-g to get out, and I noticed that the file had
>> actually been opened, so I just visited the buffer, this time the contents of
>> the file appeared, but my org-tables are not fontified at all.
>>
>> Just now I tried again, this time I toggled "debug on error" on, closed the
>> file, and tried to open the file, again, Emacs locks up, hit C-g and my emacs
>> revived, again, the file had been opened, just didn't show up. So I visited the
>> buffer, this time my org-tables are fontified properly.
>>
>> What's the problem do you think this could be?
>>
>>
> Sounds like an infinite loop, but there isn't enough information to
> determine where. Can you set debug-on-quit, try again and post the
> backtrace?
>

I tried and failed to reproduce the problem.

In a private communication (I hope he reposts it to the list), the OP
said that he *had* turned on debug-on-quit (he misspoke when he said
debug-on-error) but there was no backtrace when he pressed C-g (that in
itself indicates a problem, either with emacs or with the OP's setup.)
He mentioned that he was using a derived mode, so I tried to reproduce
the problem with the following minimal org file:

--8<---------------cut here---------------start------------->8---
(add-to-list 'load-path "~/src/emacs/org/org-mode/lisp")
(add-to-list 'load-path "~/src/emacs/org/org-mode/contib/lisp")

(require 'org-loaddefs)

(define-derived-mode ndk-mode org-mode "ndk")

(add-to-list 'auto-mode-alist  '("\\.ndk$" . ndk-mode))
--8<---------------cut here---------------end--------------->8---

I copied an org file (albeit a small one: 15K - I don't have anything
as big as the OP's 3Mb file) to foo.ndk and started emacs with

 emacs -Q -l /path/to/minimal/min.org.el foo.ndk

Everything works as expected and I don't get a hang/inf-loop or any
other problem.

It may be that hack-local-variables takes a long time to process a large
file, although I don't think so: iirc, it limits itself to a tail of the
file of a given size, or the last "page" of the file (demarcated by ^L),
whichever is smaller.

Does CPU utilization go to 100% (on the core that emacs is running on)
when emacs is unresponsive?  Does emacs -Q with a minimal org file as
above solve the problem (i.e. is the problem with the OP's .emacs)?

Questions, questions...

Nick