Re: [elpa] externals/org ee0961ba31: lisp/org-table.el: fix warning about `eq' usage

Re: [elpa] externals/org ee0961ba31: lisp/org-table.el: fix warning about `eq' usage

[Stefan Monnier]

>     This change does not affect the behavior of `org-table-make-reference'
>     because `eq' treats all instances of the empty string as the same
>     object anyway, e.g., `(eq (string-trim "aaabbb" "a+" "b+") "")' ==> t.

Not quite so: (eq (string-to-multibyte "") "") => nil


-- Stefan

Re: [elpa] externals/org ee0961ba31: lisp/org-table.el: fix warning about `eq' usage

[Karl Fogel]

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Stefan Monnier wrote:
>> This change does not affect the behavior of
>> `org-table-make-reference' because `eq' treats all instances
>> of the empty string as the same object anyway, e.g., 
>> `(eq (string-trim "aaabbb" "a+" "b+") "")' ==> t.
>
>Not quite so: (eq (string-to-multibyte "") "") => nil

Thank you for noticing this, Stefan.

I did many tests with `eq' and various kinds of generated empty 
strings before writing that commit message -- but, alas, I didn't 
think of testing with a multibyte string.  (I also looked in the 
documentation, and the fact that there was no explicit mention of 
all empty strings being the same object should have tipped me 
off!)

So, I believe this means there is an error in that commit message. 
I've attached the commitinfo below for easy reference, with 
'inline' disposition.

However, the code change itself remains correct... I think?  That 
is: the previous code presumably had a latent bug, in that there 
*could* have been times when the `eq' test would fail when 
comparing against a multibyte empty string.

I don't know much about how Org Mode gets merged into Emacs, nor 
whether there are opportunities for rebasing anywhere along the 
way in that process.  If there's a way to update that commit 
message, then I'd do so (I can post a new one here).  But if 
there's no such opportunity, then so be it: I'll be on the 
permanent record with a technical mistake in a log message.  I'm 
sure it wouldn't be the first time :-/.

Best regards,
-Karl


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commit ee0961ba3170f7bc89c2f6fabda4b6ea2e7a2c88
Author:     Karl Fogel <kfogel@red-bean.com>
AuthorDate: Mon Oct 30 10:33:29 2023 -0500
Commit:     Bastien Guerry <bzg@gnu.org>
CommitDate: Tue Oct 31 21:38:23 2023 +0100

    lisp/org-table.el: fix warning about `eq' usage
    
    * lisp/org-table.el (org-table-make-reference): Use `equal' instead of
    `eq' to compare strings.
    
    This change makes the following warning go away:
    
      Warning (comp): org-table.el:2867:23: \
      Warning: `eq' called with literal string that may never match (arg 2)
    
    This change does not affect the behavior of `org-table-make-reference'
    because `eq' treats all instances of the empty string as the same
    object anyway, e.g., `(eq (string-trim "aaabbb" "a+" "b+") "")' ==> t.
    The only effect of this change is to eliminate the warning.

M	lisp/org-table.el

Re: [elpa] externals/org ee0961ba31: lisp/org-table.el: fix warning about `eq' usage

[Bastien]

Hi Karl,

Karl Fogel <kfogel@red-bean.com> writes:

> I don't know much about how Org Mode gets merged into Emacs, nor
> whether there are opportunities for rebasing anywhere along the way in
> that process.  If there's a way to update that commit message, then
> I'd do so (I can post a new one here).  But if there's no such
> opportunity, then so be it: I'll be on the permanent record with a
> technical mistake in a log message.  I'm sure it wouldn't be the first
> time :-/.

So be it!  It isn't the first time for many of us :)

Thanks again for the fix, best,

-- 
 Bastien

Re: [elpa] externals/org ee0961ba31: lisp/org-table.el: fix warning about `eq' usage

[Stefan Monnier]

> So be it!  It isn't the first time for many of us :)

I'm not worried about such problems, indeed.
My message was only meant to spread awareness.


        Stefan

Re: [elpa] externals/org ee0961ba31: lisp/org-table.el: fix warning about `eq' usage

[Karl Fogel]

On 01 Nov 2023, Stefan Monnier wrote:
>> So be it!  It isn't the first time for many of us :)
>
>I'm not worried about such problems, indeed.
>My message was only meant to spread awareness.

Well, thanks for doing so -- I was glad to learn.

Best regards,
-Karl