From dc64aadd9b124df37fcdf2f6dc057b61cf05a473 Mon Sep 17 00:00:00 2001
From: Tobias Geerinckx-Rice <me@tobias.gr>
Date: Sun, 15 Nov 2020 20:36:32 +0100
Subject: [PATCH] ui: Ignore empty $PAGER variables.

* guix/ui.scm (call-with-paginated-output-port): Treat "" as unset.
---
 guix/ui.scm | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/guix/ui.scm b/guix/ui.scm
index 66614eef7c..584afc65dd 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -1673,8 +1673,11 @@ zero means that PACKAGE does not match any of REGEXPS."
       ;; instead of 'r': this strips hyperlinks but allows 'less' to make a
       ;; good estimate of the line length.
       (let ((pager (with-environment-variables `(("LESS" ,less-options))
-                     (open-pipe (or (getenv "GUIX_PAGER") (getenv "PAGER")
-                                    "less")
+                     ;; Ignore environment variables set to "" as if unset.
+                     (open-pipe (find (lambda (s) (and s (not (string=? "" s))))
+                                      (list (getenv "GUIX_PAGER")
+                                            (getenv "PAGER")
+                                            "less"))
                                 OPEN_WRITE))))
         (dynamic-wind
           (const #t)
-- 
2.29.2