net: rewrite toLower more clearly

Rob suggested this change.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/43670044

diff --git a/src/pkg/net/lookup_plan9.go b/src/pkg/net/lookup_plan9.go
index 8003d177d0642f7788db94871e597850072a8205..a755ff2aacc49e3c3f79dd78b10a2ea522ce9932 100644 (file)
--- a/src/pkg/net/lookup_plan9.go
+++ b/src/pkg/net/lookup_plan9.go
@@ -73,23 +73,21 @@ func queryDNS(addr string, typ string) (res []string, err error) {
 // ASCII is sufficient to handle the IP protocol names and allow
 // us to not depend on the strings and unicode packages.
 func toLower(in string) string {
-       isAlreadyLowerCase := true
        for _, c := range in {
                if 'A' <= c && c <= 'Z' {
-                       isAlreadyLowerCase = false
-                       break
-               }
-       }
-       if isAlreadyLowerCase {
-               return in
-       }
-       out := []byte(in)
-       for i, c := range out {
-               if 'A' <= c && c <= 'Z' {
-                       out[i] += 'a' - 'A'
+                       // Has upper case; need to fix.
+                       out := []byte(in)
+                       for i := 0; i < len(in); i++ {
+                               c := in[i]
+                               if 'A' <= c && c <= 'Z' {
+                                       c += 'a' - 'A'
+                               }
+                               out[i] = c
+                       }
+                       return string(out)
                }
        }
-       return string(out)
+       return in
 }
 
 // lookupProtocol looks up IP protocol name and returns