bug#36301: Package-Requires should support multiple lines

[Thomas Fitzsimmons]

Hi,

The Package-Requires line in my GNU ELPA package, Excorporate, is much
longer than 80 characters and I would like to wrap it.  It would be nice
if package.el allowed Package-Requires to span multiple lines (see
patch).  It's probably too late to change this but I thought I'd file a
bug report anyway.

Thomas

diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 46f7c91272..5c9b12732d 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -1016,7 +1016,8 @@ package-buffer-info
     (narrow-to-region start (point))
     (require 'lisp-mnt)
     ;; Use some headers we've invented to drive the process.
-    (let* ((requires-str (lm-header "package-requires"))
+    (let* ((requires-str
+            (mapconcat 'identity (lm-header-multiline "package-requires") " "))
            ;; Prefer Package-Version; if defined, the package author
            ;; probably wants us to use it.  Otherwise try Version.
            (pkg-version