gnu: emacs-helpful: Update to 0.21.

* gnu/packages/patches/emacs-helpful-fix-tests.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it here.
* gnu/packages/emacs-xyz.scm (emacs-helpful): Update to 0.21.
[source]<patches>: Use it here.

gnu/local.mk

@@ -1097,6 +1097,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/emacs-fix-scheme-indent-function.patch	\
   %D%/packages/patches/emacs-json-reformat-fix-tests.patch	\
   %D%/packages/patches/emacs-haskell-mode-no-redefine-builtin.patch	\
+  %D%/packages/patches/emacs-helpful-fix-tests.patch	\
   %D%/packages/patches/emacs-highlight-stages-add-gexp.patch	\
   %D%/packages/patches/emacs-lispy-fix-thread-last-test.patch   \
   %D%/packages/patches/emacs-native-comp-driver-options.patch   \

gnu/packages/emacs-xyz.scm

@@ -24363,20 +24363,19 @@ downloading manager for Emacs.")
       (license license:gpl3+))))
 
 (define-public emacs-helpful
-  (let ((commit "1c98f6f06a85def5d34c735f8cd407f20cebddf9")
-        (revision "1"))
   (package
     (name "emacs-helpful")
-      (version (git-version "0.19" revision commit))
+    (version "0.21")
     (source
      (origin
        (method git-fetch)
        (uri (git-reference
              (url "https://github.com/Wilfred/helpful")
-               (commit commit)))
+             (commit version)))
        (file-name (git-file-name name version))
        (sha256
-          (base32 "18b5hjfji51zxjrxhkklxx3j9svk295awmxv8n95mp8ilas2kd3l"))))
+        (base32 "03afgdbs5nmhw833svrqky7fmfs1zlvqzcj7j5g29sakivs60xqc"))
+       (patches (search-patches "emacs-helpful-fix-tests.patch"))))
     (build-system emacs-build-system)
     (propagated-inputs
      (list emacs-dash emacs-elisp-refs emacs-f emacs-s))
@@ -24406,7 +24405,7 @@ functions.
 @item Trace, disassemble functions from inside Helpful.  This is discoverable
 and doesn't require memorisation of commands.
 @end itemize\n")
-      (license license:gpl3+))))
+    (license license:gpl3+)))
 
 (define-public emacs-logview
   (package

gnu/packages/patches/emacs-helpful-fix-tests.patch

@@ -0,0 +1,28 @@
+From 233e254bbe44f70ca899a506b3706af489228fda Mon Sep 17 00:00:00 2001
+From: aagon <aymeric.agon@hotmail.fr>
+Date: Thu, 10 Aug 2023 20:03:52 +0200
+Subject: [PATCH] Repair helpful--display-implementations test for emacs 29.1
+
+---
+ test/helpful-unit-test.el | 8 ++++++--
+ 1 file changed, 6 insertions(+), 2 deletions(-)
+
+diff --git a/test/helpful-unit-test.el b/test/helpful-unit-test.el
+index 0f5177b..0716b0d 100644
+--- a/test/helpful-unit-test.el
++++ b/test/helpful-unit-test.el
+@@ -1089,8 +1089,12 @@ find the source code."
+   (require 'xref)
+   (helpful-function 'xref-location-marker)
+   (should (s-contains-p "Implementations" (buffer-string)))
+-  (should (s-contains-p "((l xref-file-location))" (buffer-string)))
+-  (should (s-contains-p "((l xref-buffer-location))" (buffer-string))))
++  (should (if (version< emacs-version "29.1")
++	      (s-contains-p "((l xref-file-location))" (buffer-string))
++	    (s-contains-p "(xref-location-marker (L xref-file-location))" (buffer-string))))
++  (should (if (version< emacs-version "29.1")
++	      (s-contains-p "((l xref-buffer-location))" (buffer-string))
++	    (s-contains-p "(xref-location-marker (L xref-buffer-location))" (buffer-string)))))
+ 
+ (defun helpful--boring-advice (orig-fn &rest args)
+   (apply orig-fn args))