This patch fixes a bug that made the mixer command enter
an infinite loop when instructed to set the value of a device
to an empty string (e.g., `mixer vol ""`).
Additionally, some tests for mixer(8) are being added.
PR: 240039
Reviewed by: hselasky, mav
Approved by: src (hselasky, mav)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D21409
that it encounters (such as invalid device), but does print usage upon
this error...
but otherwise allows complex commands such as:
mixer -f /dev/mixer4 synth line 50 -rec mic +rec line =rec cd ^rec mix
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.