2 files changed, 15 insertions, 12 deletions

diff --git a/corecfg/utils.go b/corecfg/utils.go
index f6018b75b9..c666d139d1 100644
--- a/corecfg/utils.go
+++ b/corecfg/utils.go
@@ -32,15 +32,18 @@ var rx = regexp.MustCompile(`^[ \t]*(#?)[ \t#]*([a-z_]+)=(.*)$`)
 // updateKeyValueStream updates simple key=value files with comments.
 // Example for such formats are: /etc/environment or /boot/uboot/config.txt
 //
-// An r io.Reader and a configuration "patch" is taken as input, the r is
-// read line-by-line and any line and any required configuration change from
-// the "config" input is applied. If changes need to be written a []string
+// An r io.Reader, map of supported config keys and a configuration
+// "patch" is taken as input, the r is read line-by-line and any line
+// and any required configuration change from the "config" input is
+// applied.
+//
+// If changes need to be written a []string
 // that contains the full file is returned. On error an error is returned.
-func updateKeyValueStream(r io.Reader, allConfig map[string]bool, newConfig map[string]string) (toWrite []string, err error) {
+func updateKeyValueStream(r io.Reader, supportedConfigKeys map[string]bool, newConfig map[string]string) (toWrite []string, err error) {
	cfgKeys := make([]string, len(newConfig))
	i := 0
	for k := range newConfig {
-	if !allConfig[k] {
+	if !supportedConfigKeys[k] {
	return nil, fmt.Errorf("cannot set unsupported configuration value %q", k)
	}
	cfgKeys[i] = k
@@ -55,7 +58,7 @@ func updateKeyValueStream(r io.Reader, allConfig map[string]bool, newConfig map[
	for scanner.Scan() {
	line := scanner.Text()
	matches := rx.FindStringSubmatch(line)
-	if len(matches) > 0 && allConfig[matches[2]] {
+	if len(matches) > 0 && supportedConfigKeys[matches[2]] {
	wasComment := (matches[1] == "#")
	key := matches[2]
	oldValue := matches[3]
diff --git a/corecfg/utils_test.go b/corecfg/utils_test.go
index e13a8eaf0f..7283b4a1fe 100644
--- a/corecfg/utils_test.go
+++ b/corecfg/utils_test.go
@@ -34,9 +34,9 @@ var _ = Suite(&utilsSuite{})
 func (s *utilsSuite) TestUpdateKeyValueStreamNoNewConfig(c *C) {
	in := bytes.NewBufferString("foo=bar")
	newConfig := map[string]string{}
-	allConfig := map[string]bool{}
+	supportedConfigKeys := map[string]bool{}
 
-	toWrite, err := corecfg.UpdateKeyValueStream(in, allConfig, newConfig)
+	toWrite, err := corecfg.UpdateKeyValueStream(in, supportedConfigKeys, newConfig)
	c.Check(err, IsNil)
	c.Check(toWrite, IsNil)
 }
@@ -44,22 +44,22 @@ func (s *utilsSuite) TestUpdateKeyValueStreamNoNewConfig(c *C) {
 func (s *utilsSuite) TestUpdateKeyValueStreamConfigNotInAllConfig(c *C) {
	in := bytes.NewBufferString("")
	newConfig := map[string]string{"unsupported-options": "cannot be set"}
-	allConfig := map[string]bool{
+	supportedConfigKeys := map[string]bool{
	"foo": true,
	}
 
-	_, err := corecfg.UpdateKeyValueStream(in, allConfig, newConfig)
+	_, err := corecfg.UpdateKeyValueStream(in, supportedConfigKeys, newConfig)
	c.Check(err, ErrorMatches, `cannot set unsupported configuration value \"unsupported-options"`)
 }
 
 func (s *utilsSuite) TestUpdateKeyValueStreamOneChange(c *C) {
	in := bytes.NewBufferString("foo=bar")
	newConfig := map[string]string{"foo": "baz"}
-	allConfig := map[string]bool{
+	supportedConfigKeys := map[string]bool{
	"foo": true,
	}
 
-	toWrite, err := corecfg.UpdateKeyValueStream(in, allConfig, newConfig)
+	toWrite, err := corecfg.UpdateKeyValueStream(in, supportedConfigKeys, newConfig)
	c.Check(err, IsNil)
	c.Check(toWrite, DeepEquals, []string{"foo=baz"})
 }