Merge pull request go-git#128 from cristaloleg/minor-perf-fixes

Use EqualFold for comparison

Author: mcuadros

plumbing/format/config/option.go

@@ -19,7 +19,7 @@ type Options []*Option
 // IsKey returns true if the given key matches
 // this option's key in a case-insensitive comparison.
 func (o *Option) IsKey(key string) bool {
-	return strings.ToLower(o.Key) == strings.ToLower(key)
+	return strings.EqualFold(o.Key, key)
 }
 
 func (opts Options) GoString() string {

plumbing/format/config/section.go

@@ -61,7 +61,7 @@ func (s Subsections) GoString() string {
 
 // IsName checks if the name provided is equals to the Section name, case insensitive.
 func (s *Section) IsName(name string) bool {
-	return strings.ToLower(s.Name) == strings.ToLower(name)
+	return strings.EqualFold(s.Name, name)
 }
 
 // Option return the value for the specified key. Empty string is returned if