cros_workon: make --board and --host not exclusive

cros_workon: make --board and --host not exclusive

This fixes a case where you can't specify host if you have a
default board set.

BUG=6039
TEST=cros_workon start with --host, --board, both

Change-Id: Iad0d3f646dde10cc4adc4131e93f75fabe92f392

[Tan Gao, 2010-08-26 23:03:41]

LGTM

[Mandeep Singh Baines, 2010-08-27 01:47:01]

http://codereview.chromium.org/3157044/diff/1/2
File cros_workon (right):

http://codereview.chromium.org/3157044/diff/1/2#newcode54
cros_workon:54: FLAGS_board="" # kill board
I'm uncomfortable with modifying a shflags parameter. Might be cleaner to just
remove this check and modify the if statement below.

http://codereview.chromium.org/3157044/diff/1/2#newcode58
cros_workon:58: if [ -n "${FLAGS_board}" ]; then
What if this were changed to [ -n "${FLAGS_host}" ]

[zbehan, 2010-08-27 02:17:51]

Well, it's tested and it works like this.

Also, tgao already LGTM'ed so i pushed, but if you want, I can fix the
comments in a separate CL.

On Thu, Aug 26, 2010 at 6:47 PM, <msb@chromium.org> wrote:

>
> http://codereview.chromium.org/3157044/diff/1/2
> File cros_workon (right):
>
> http://codereview.chromium.org/3157044/diff/1/2#newcode54
> cros_workon:54: FLAGS_board="" # kill board
> I'm uncomfortable with modifying a shflags parameter. Might be cleaner

to just remove this check and modify the if statement below.
>

All shflags processing happens on line 39. After that, all flags are game
for killing, clobbering, destroying. While it may not necessarily be a super
straightforward behaviour, it does the job and is not very dirty either.


> http://codereview.chromium.org/3157044/diff/1/2#newcode58
> cros_workon:58: if [ -n "${FLAGS_board}" ]; then
> What if this were changed to [ -n "${FLAGS_host}" ]


Well, for host you need emerge and for board you need emerge(dash)something,
that's why it's split into two branches instead of just doing
emerge-${FLAGS_board}, whether that is empty or set, because for host, there
is no emerge-. I probably don't see what changing this check would fix.