remount dist if permissions aren't appropriate to save annoyance

Reference: /n/atom/patch/applied2013/distperms
Date: Wed Jun 26 03:09:07 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /rc/bin/apatch/defs	Wed Jun 26 03:08:31 2013
+++ /rc/bin/apatch/defs	Wed Jun 26 03:08:31 2013
@@ -1,6 +1,6 @@
 P=atom
 S=atom
-M=sources@9atom.org
+M=(sources@9atom.org)
 MS=sources@9atom.org
 PD=/n/$P/patch
 SD=/n/$S/plan9
@@ -20,15 +20,26 @@
 	}
 }
 
+fn canwrite {
+	{
+		touch  $1 &&
+			rm -f $1
+	} >[2]/dev/null
+}
+
 fn mountdist {
 	test -e /n/dist/386 || bind  $SD /n/dist || fail no dist
 	test -e /n/dist/386 || fail /root/386 does not exist
 
 	if(~ $1 -w){
-		{
-			touch  /n/dist/lib/xxx &&
-			rm -f /n/dist/lib/xxx
-		} >[2]/dev/null || fail no permission to write /n/dist/lib
+		canwrite /n/dist/lib/xxx || {
+			# try to remount
+			unmount /n/$P	|| fatal remount
+			mountfs -a	|| fail mountfs
+			bind  $SD /n/dist	|| fail no dist
+			test -e /n/dist/386	|| fail /root/386 does not exist
+			canwrite /n/dist/lib/xxx || fail no permission to write /n/dist/lib
+		}
 	}
 }
 
@@ -49,4 +60,11 @@
 
 fn must {
 	$* || fail $*
+}
+
+fn applyxxx {
+	if(! ~ $#* 0 && test -e $1)
+		grep -v -f $1 | sed 's/^../xxx &/' | rc
+	if not
+		sed 's/^../xxx &/' | rc
 }