master 3c0e51e4e5 2/3: (battery-status-function) Fix errors in Termux

[Lars Ingebrigtsen]

branch: master
commit 3c0e51e4e59f45d6f6268223fa4b91de0053b36a
Author: Lucien Cartier-Tilet <lucien@phundrak.com>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    (battery-status-function) Fix errors in Termux
    
    * lisp/battery.el (battery-status-function): In Termux, neither
    /sys/ or /proc/ are readable on phones that are not rooted. This
    patch makes Emacs verify if they are readable before it attemps
    reading them (bug#53026).
    
    Copyright-paperwork-exempt: yes
---
 lisp/battery.el | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lisp/battery.el b/lisp/battery.el
index 45334163fa..b7b81a11a1 100644
--- a/lisp/battery.el
+++ b/lisp/battery.el
@@ -96,12 +96,14 @@ Value does not include \".\" or \"..\"."
   (cond ((member battery-upower-service (dbus-list-activatable-names))
          #'battery-upower)
         ((and (eq system-type 'gnu/linux)
+              (file-readable-p "/sys/")
               (battery--find-linux-sysfs-batteries))
          #'battery-linux-sysfs)
        ((and (eq system-type 'gnu/linux)
              (file-directory-p "/proc/acpi/battery"))
         #'battery-linux-proc-acpi)
        ((and (eq system-type 'gnu/linux)
+              (file-readable-p "/proc/")
               (file-readable-p "/proc/apm"))
          #'battery-linux-proc-apm)
        ((and (eq system-type 'berkeley-unix)