bug#10332: battery.el not working when multiple batteries are present

[Dan Nicolaescu]

On a machine that has a normal battery and another one that can be put
in the CD/DVD slot M-x battery does not work when both batteries are
present.  

Only one battery is discharged at a time, but that seems to confuse
battery.el when computing `rate-type' for the battery not being
discharged.

Here's a proposed patch.



=== modified file 'lisp/battery.el'
--- lisp/battery.el     2011-10-19 12:54:24 +0000
+++ lisp/battery.el     2011-10-20 21:40:57 +0000
@@ -337,14 +337,15 @@
               (setq charging-state (match-string 1)))
          (when (re-search-forward "present rate: +\\([0-9]+\\) \\(m[AW]\\)$"
                                   nil t)
-           (setq rate (+ (or rate 0) (string-to-number (match-string 1)))
-                 rate-type (or (and rate-type
+           (setq rate (+ (or rate 0) (string-to-number (match-string 1))))
+           (when (> rate 0)
+             (setq rate-type (or (and rate-type
                                     (if (string= rate-type (match-string 2))
                                         rate-type
                                       (error
                                        "Inconsistent rate types (%s vs. %s)"
                                        rate-type (match-string 2))))
-                               (match-string 2))))
+                                 (match-string 2)))))
          (when (re-search-forward "remaining capacity: +\\([0-9]+\\) m[AW]h$"
                                   nil t)
            (setq capacity