tests: New helper cmp_out1

Factor out of cmp_out, then make it optionally take an explicit
expected result.

Signed-off-by: Markus Armbruster <armbru@pond.sub.org>

tests/test-common.sh

@@ -210,17 +210,30 @@ cmp_logs_xdump()
 
 cmp_out()
 {
-    local i exp act nrm
+    local i
 
     for i
-    do
+    do cmp_out1 "$i"
-	exp="$testdir/${i##*/}"
+    done
-	act="sandbox/$i"
+}
-	nrm="sandbox/normalized-${i##*/}"
+
+cmp_out1()
+{
+    local i=$1 exp="${2-$testdir/${1##*/}}"
+    local act="sandbox/$i"
+    local nrm="sandbox/normalized-${i##*/}"
 
     if [ ! -e "$exp" ]
     then
 	case "$i" in
+	*.status)
+	    exp=sandbox/ok.status
+	    echo 0 >sandbox/ok.status
+	    ;;
+	*)
+	    [ ! -e "$act" ] && return
+	    exp=/dev/null
+	    ;;
 	    *.status)   exp=sandbox/ok.status; echo 0 >sandbox/ok.status ;;
 	    *)		exp=/dev/null ;;
 	esac
@@ -249,5 +262,4 @@ cmp_out()
 	failed=y
 	echo "$i FAIL"
     fi
-    done
 }