[9front] [PATCH] Preserve nobootprompt

[9front] [PATCH] Preserve nobootprompt

[Jacob Moody]

In our bootrc we currently completely blank out
nobootprompt. If you are attempting to do a warm
reboot into another kernel, it is quite annoying
to respecify it for each boot. We were blanking it
(seemingly) due to how rc(1) stashes lists in to /env/, which is
using a null between list members. This would cause the kernel
to skip all arguments past the first when doing successive reboots.

Instead we can 'flatten' the variable back in to '#ec' on the way
out to preserve things how we found them.

---
diff 1b5ea51ee1203952900fafc0def48985d900f7a7 uncommitted
--- a//sys/src/9/boot/bootrc
+++ b//sys/src/9/boot/bootrc
@@ -74,7 +74,6 @@
 			ask bootargs ' is (tcp, tls, il, local!device)' $"bootargs
 		}
 		if not bootargs=$nobootprompt
-		nobootprompt=()
 		mn=`{echo $bootargs | sed 's,!, ,'}
 		ma=$mn(2-)
 		mn=$mn(1)
@@ -146,6 +145,9 @@
 		if not
 			init=($init -t)
 	}
+
+	if(! ~ $#nobootprompt 0)
+		echo -n $nobootprompt > '#ec/nobootprompt'

 	# remove enviroment variables
 	rm -f '#e/'^$mt '#e/'? '#e/'?? '#e/fn#'*