alsamixer: fix division by zero

The attempt to divide by max-min fails if a control has only one valid
value.  In this case, adjust the maximum so that the computation can
succeed; the control will look like 0%.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

diff --git a/alsamixer/mixer_display.c b/alsamixer/mixer_display.c
index 9eadcc9a4b92aab43e8b49a5d3dfceaf0a8489d6..260c9b03bb15b871c06a5d83fb64552ccb6060ae 100644 (file)
--- a/alsamixer/mixer_display.c
+++ b/alsamixer/mixer_display.c
@@ -462,6 +462,8 @@ static void display_control(unsigned int control_index)
                        err = snd_mixer_selem_get_capture_volume_range(control->elem, &min, &max);
                if (err < 0)
                        return;
+               if (min == max)
+                       max = min + 1;
 
                if (control->flags & IS_ACTIVE)
                        wattrset(mixer_widget.window, 0);