1 files changed, 25 insertions, 26 deletions
diff --git a/bpfix/bpfix/bpfix.go b/bpfix/bpfix/bpfix.go
index fcd4fecf..67a59099 100644
--- a/bpfix/bpfix/bpfix.go
+++ b/bpfix/bpfix/bpfix.go
@@ -41,20 +41,19 @@ func (r FixRequest) AddAll() (result FixRequest) {
 
 // FixTree repeatedly applies the fixes listed in the given FixRequest to the given File
 // until there is no fix that affects the tree
-func FixTree(tree *parser.File, config FixRequest) (fixed *parser.File, err error) {
+func FixTree(tree *parser.File, config FixRequest) error {
 	prevIdentifier, err := fingerprint(tree)
 	if err != nil {
-		return nil, err
+		return err
 	}
 
-	fixed = tree
 	maxNumIterations := 20
 	i := 0
 	for {
-		fixed, err = fixTreeOnce(fixed, config)
+		err = fixTreeOnce(tree, config)
 		newIdentifier, err := fingerprint(tree)
 		if err != nil {
-			return nil, err
+			return err
 		}
 		if bytes.Equal(newIdentifier, prevIdentifier) {
 			break
@@ -65,11 +64,11 @@ func FixTree(tree *parser.File, config FixRequest) (fixed *parser.File, err erro
 		// detect infinite loop
 		i++
 		if i >= maxNumIterations {
-			return nil, fmt.Errorf("Applied fixes %s times and yet the tree continued to change. Is there an infinite loop?", i)
+			return fmt.Errorf("Applied fixes %s times and yet the tree continued to change. Is there an infinite loop?", i)
 			break
 		}
 	}
-	return fixed, err
+	return err
 }
 
 // returns a unique identifier for the given tree that can be used to determine whether the tree changed
@@ -81,20 +80,19 @@ func fingerprint(tree *parser.File) (fingerprint []byte, err error) {
 	return bytes, nil
 }
 
-func fixTreeOnce(tree *parser.File, config FixRequest) (fixed *parser.File, err error) {
+func fixTreeOnce(tree *parser.File, config FixRequest) error {
 	if config.simplifyKnownRedundantVariables {
-		tree, err = simplifyKnownPropertiesDuplicatingEachOther(tree)
+		err := simplifyKnownPropertiesDuplicatingEachOther(tree)
 		if err != nil {
-			return nil, err
+			return err
 		}
 	}
-	return tree, err
+	return nil
 }
 
-func simplifyKnownPropertiesDuplicatingEachOther(tree *parser.File) (fixed *parser.File, err error) {
+func simplifyKnownPropertiesDuplicatingEachOther(tree *parser.File) error {
 	// remove from local_include_dirs anything in export_include_dirs
-	fixed, err = removeMatchingModuleListProperties(tree, "export_include_dirs", "local_include_dirs")
-	return fixed, err
+	return removeMatchingModuleListProperties(tree, "export_include_dirs", "local_include_dirs")
 }
 
 // removes from <items> every item present in <removals>
@@ -121,29 +119,30 @@ func filterExpressionList(items *parser.List, removals *parser.List) {
 }
 
 // Remove each modules[i].Properties[<legacyName>][j] that matches a modules[i].Properties[<canonicalName>][k]
-func removeMatchingModuleListProperties(tree *parser.File, canonicalName string, legacyName string) (fixed *parser.File, err error) {
+func removeMatchingModuleListProperties(tree *parser.File, canonicalName string, legacyName string) error {
 	for _, def := range tree.Defs {
 		mod, ok := def.(*parser.Module)
 		if !ok {
 			continue
 		}
-		legacy, ok := mod.GetProperty(legacyName)
-		if !ok {
-			continue
-		}
-		legacyList, ok := legacy.Value.(*parser.List)
-		if !ok {
-			continue
-		}
-		canonical, ok := mod.GetProperty(canonicalName)
+		legacyList, ok := getLiteralListProperty(mod, legacyName)
 		if !ok {
 			continue
 		}
-		canonicalList, ok := canonical.Value.(*parser.List)
+		canonicalList, ok := getLiteralListProperty(mod, canonicalName)
 		if !ok {
 			continue
 		}
 		filterExpressionList(legacyList, canonicalList)
 	}
-	return tree, nil
+	return nil
+}
+
+func getLiteralListProperty(mod *parser.Module, name string) (list *parser.List, found bool) {
+	prop, ok := mod.GetProperty(name)
+	if !ok {
+		return nil, false
+	}
+	list, ok = prop.Value.(*parser.List)
+	return list, ok
 }