[bug#44249] [PATCH v2] gnu: emacs: Make strip-double-wrap more robust

[Morgan . J . Smith]

From: Morgan Smith <Morgan.J.Smith@outlook.com>

* gnu/packages/emacs.scm (emacs) [strip-double-wrap]:
Use regex to find emacs executable. This works even when the version is
changed by package transformations (ex: version=git.master)
---
 gnu/packages/emacs.scm | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/gnu/packages/emacs.scm b/gnu/packages/emacs.scm
index 4963379d74..00441dee45 100644
--- a/gnu/packages/emacs.scm
+++ b/gnu/packages/emacs.scm
@@ -123,6 +123,9 @@
     (build-system glib-or-gtk-build-system)
     (arguments
      `(#:tests? #f                      ; no check target
+       #:modules ((guix build glib-or-gtk-build-system)
+                  (guix build utils)
+                  (ice-9 match))
        #:configure-flags (list "--with-modules"
                                "--with-cairo"
                                "--disable-build-details")
@@ -196,17 +199,13 @@
            (lambda* (#:key outputs #:allow-other-keys)
              ;; Directly copy emacs-X.Y to emacs, so that it is not wrapped
              ;; twice.  This also fixes a minor issue, where WMs would not be
-             ;; able to track emacs back to emacs.desktop.  The version is
-             ;; accessed using using THIS-PACKAGE so it "just works" for
-             ;; inherited Emacs packages of different versions.
+             ;; able to track emacs back to emacs.desktop.
              (with-directory-excursion (assoc-ref outputs "out")
-               (copy-file (string-append
-                           "bin/emacs-"
-                           ,(let ((this-version (package-version 
this-package)))
-                              (or (false-if-exception
-                                   (version-major+minor+point this-version))
-                                  (version-major+minor this-version))))
-                          "bin/emacs")
+               (copy-file
+                (match
+                    (find-files "bin" (file-name-predicate "^emacs-"))
+                  (((? string? string)) string))
+                "bin/emacs")
                #t)))
          (add-before 'reset-gzip-timestamps 'make-compressed-files-writable
            ;; The 'reset-gzip-timestamps phase will throw a permission error
-- 
2.29.1