bug#32024: 27.0; [PATCH] `imenu--generic-function'

bug#32024: 27.0; [PATCH] `imenu--generic-function'

[Drew Adams]

[-- Attachment #1: Type: text/plain, Size: 1064 bytes --]

Attached is a patch for two bugs in `imenu--generic-function'.  I ran
into them when using a function value for argument REGEXP, though
neither has to do particularly with that use case.  Instead, they both
have to do with the case where items are within comments or strings,
which might be skipped.

1. When checking whether the current item is inside a comment or string,
   it's necessary to first move point to position START.  Otherwise, the
   test is made at bol (which might not be within a comment or string,
   even though the START position is).

2. At the end, it's necessary to remove any empty menus that could have
   been added.  That can happen because of skipping things inside
   comments or strings.

In GNU Emacs 27.0.50 (build 3, x86_64-w64-mingw32)
 of 2018-03-21
Repository revision: e70d0c9e66d7a8609450b2889869d16aeb0363b5
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install -C 'CFLAGS=-O2 -static -g3''

[-- Attachment #2: imenu-2018-06-30.patch --]
[-- Type: application/octet-stream, Size: 1174 bytes --]

diff -u imenu.el imenu-2018-06-30-patched.el
--- imenu.el	2018-06-30 15:34:46.614653600 -0700
+++ imenu-2018-06-30-patched.el	2018-06-30 15:44:17.946791000 -0700
@@ -817,7 +817,7 @@
 		  ;; Insert the item unless it is already present.
 		  (unless (or (member item (cdr menu))
                               (and imenu-generic-skip-comments-and-strings
-                                   (nth 8 (syntax-ppss))))
+                                   (save-excursion (goto-char start) (nth 8 (syntax-ppss)))))
 		    (setcdr menu
 			    (cons item (cdr menu)))))
 		;; Go to the start of the match, to make sure we
@@ -831,7 +831,10 @@
 	(setcdr item (sort (cdr item) 'imenu--sort-by-position))))
     (let ((main-element (assq nil index-alist)))
       (nconc (delq main-element (delq 'dummy index-alist))
-	     (cdr main-element)))))
+             (cdr main-element)))
+    ;; Remove any empty menus.  That can happen because of skipping things inside comments or strings.
+    (when (consp (car index-alist))
+      (setq index-alist  (imenup-delete-if-not (lambda (it) (cdr it)) index-alist)))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;;

bug#32024: 27.0; [PATCH] `imenu--generic-function'

[Eli Zaretskii]

> Date: Sat, 30 Jun 2018 15:53:22 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> 
> Attached is a patch for two bugs in `imenu--generic-function'.  I ran
> into them when using a function value for argument REGEXP, though
> neither has to do particularly with that use case.  Instead, they both
> have to do with the case where items are within comments or strings,
> which might be skipped.
> 
> 1. When checking whether the current item is inside a comment or string,
>    it's necessary to first move point to position START.  Otherwise, the
>    test is made at bol (which might not be within a comment or string,
>    even though the START position is).
> 
> 2. At the end, it's necessary to remove any empty menus that could have
>    been added.  That can happen because of skipping things inside
>    comments or strings.

Thanks.

Applying this produces the following warning from the byte compiler:

  In end of data:
  imenu.el:1056:1:Warning: the function `imenup-delete-if-not' is not known to
      be defined.

And indeed, I cannot find that function anywhere in Emacs.

bug#32024: 27.0; [PATCH] `imenu--generic-function'

[Drew Adams]

> > Attached is a patch for two bugs in `imenu--generic-function'.  I ran
> > into them when using a function value for argument REGEXP, though
> > neither has to do particularly with that use case.  Instead, they both
> > have to do with the case where items are within comments or strings,
> > which might be skipped.
> >
> > 1. When checking whether the current item is inside a comment or
> string,
> >    it's necessary to first move point to position START.  Otherwise,
> the
> >    test is made at bol (which might not be within a comment or string,
> >    even though the START position is).
> >
> > 2. At the end, it's necessary to remove any empty menus that could have
> >    been added.  That can happen because of skipping things inside
> >    comments or strings.
> 
> Thanks.
> 
> Applying this produces the following warning from the byte compiler:
> 
>   In end of data:
>   imenu.el:1056:1:Warning: the function `imenup-delete-if-not' is not
>   known to be defined.
> 
> And indeed, I cannot find that function anywhere in Emacs.

Sorry about that.  Can you please substitute the equivalent
function from Emacs, `cl-delete-if-not' (in `cl-seq.el')?

(I took this from my `imenu+.el' code, and that library
does not want to load `cl-seq.el' just for this, so it
defines the function separately.)

bug#32024: 27.0; [PATCH] `imenu--generic-function'

[Eli Zaretskii]

> Date: Sat, 7 Jul 2018 07:27:52 -0700 (PDT)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 32024@debbugs.gnu.org
> 
> Sorry about that.  Can you please substitute the equivalent
> function from Emacs, `cl-delete-if-not' (in `cl-seq.el')?

Done, thanks.