3 files changed, 12 insertions, 9 deletions
diff --git a/src/pkg/bytes/buffer_test.go b/src/pkg/bytes/buffer_test.go
index 4d3fca872..bb6593774 100644
--- a/src/pkg/bytes/buffer_test.go
+++ b/src/pkg/bytes/buffer_test.go
@@ -164,7 +164,7 @@ func TestMixedReadsAndWrites(t *testing.T) {
 
 		rlen := rand.Intn(len(data));
 		fub := make([]byte, rlen);
-		n, err := buf.Read(fub);
+		n, _ := buf.Read(fub);
 		s = s[n : len(s)];
 	}
 	empty(t, "TestMixedReadsAndWrites (2)", &buf, s, make([]byte, buf.Len()));
diff --git a/src/pkg/bytes/bytes.go b/src/pkg/bytes/bytes.go
index d4eb4c7d9..30ac4580b 100644
--- a/src/pkg/bytes/bytes.go
+++ b/src/pkg/bytes/bytes.go
@@ -190,8 +190,8 @@ func Map(mapping func(rune int) int, s []byte) []byte {
 	maxbytes := len(s);	// length of b
 	nbytes := 0;	// number of bytes encoded in b
 	b := make([]byte, maxbytes);
-	for wid, i := 0, 0; i < len(s); i += wid {
-		wid = 1;
+	for i := 0; i < len(s); {
+		wid := 1;
 		rune := int(s[i]);
 		if rune < utf8.RuneSelf {
 			rune = mapping(rune);
@@ -209,6 +209,7 @@ func Map(mapping func(rune int) int, s []byte) []byte {
 			b = nb;
 		}
 		nbytes += utf8.EncodeRune(rune, b[nbytes:maxbytes]);
+		i += wid;
 	}
 	return b[0:nbytes];
 }
@@ -232,8 +233,8 @@ func Title(s []byte) []byte {
 // removed, as defined by Unicode.
 func TrimSpace(s []byte) []byte {
 	start, end := 0, len(s);
-	for wid := 0; start < end; start += wid {
-		wid = 1;
+	for start < end {
+		wid := 1;
 		rune := int(s[start]);
 		if rune >= utf8.RuneSelf {
 			rune, wid = utf8.DecodeRune(s[start:end])
@@ -241,9 +242,10 @@ func TrimSpace(s []byte) []byte {
 		if !unicode.IsSpace(rune) {
 			break;
 		}
+		start += wid;
 	}
-	for wid := 0; start < end; end -= wid {
-		wid = 1;
+	for start < end {
+		wid := 1;
 		rune := int(s[end-1]);
 		if rune >= utf8.RuneSelf {
 			// Back up carefully looking for beginning of rune. Mustn't pass start.
@@ -257,6 +259,7 @@ func TrimSpace(s []byte) []byte {
 		if !unicode.IsSpace(rune) {
 			break;
 		}
+		end -= wid;
 	}
 	return s[start:end];
 }
diff --git a/src/pkg/bytes/bytes_test.go b/src/pkg/bytes/bytes_test.go
index 8443480e5..df4d4c2d0 100644
--- a/src/pkg/bytes/bytes_test.go
+++ b/src/pkg/bytes/bytes_test.go
@@ -216,7 +216,7 @@ func Bytes(s string) []byte {
 // Execute f on each test case.  funcName should be the name of f; it's used
 // in failure reports.
 func runStringTests(t *testing.T, f func([]byte) []byte, funcName string, testCases []StringTest) {
-	for i, tc := range testCases {
+	for _, tc := range testCases {
 		actual := string(f(Bytes(tc.in)));
 		if actual != tc.out {
 			t.Errorf("%s(%q) = %q; want %q", funcName, tc.in, actual, tc.out);
@@ -275,7 +275,7 @@ var addtests = []AddTest {
 }
 
 func TestAdd(t *testing.T) {
-	for i, test := range addtests {
+	for _, test := range addtests {
 		b := make([]byte, len(test.s), test.cap);
 		for i := 0; i < len(test.s); i++ {
 			b[i] = test.s[i]