- bufio.ReadRune fix for empty reads w/o errors

- added testcases

R=rsc
DELTA=61  (56 added, 2 deleted, 3 changed)
OCL=32831
CL=32834

diff --git a/src/pkg/bufio/bufio.go b/src/pkg/bufio/bufio.go
index c64e01b4466d34dbd322a5b41eeb49623ffa1640..295647d5a08d28294efaa6e71793205beb7ed30c 100644 (file)
--- a/src/pkg/bufio/bufio.go
+++ b/src/pkg/bufio/bufio.go
@@ -195,13 +195,11 @@ func (b *Reader) UnreadByte() os.Error {
 // rune and its size in bytes.
 func (b *Reader) ReadRune() (rune int, size int, err os.Error) {
        for b.r + utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) {
-               n := b.w - b.r;
                b.fill();
                if b.err != nil {
-                       return 0, 0, b.err
-               }
-               if b.w - b.r == n {
-                       // no bytes read
+                       if b.r == b.w {
+                               return 0, 0, b.err;
+                       }
                        break;
                }
        }

diff --git a/src/pkg/bufio/bufio_test.go b/src/pkg/bufio/bufio_test.go
index ec7f949725c0f3341291d7acfa0d9ea59d5c1124..c08f68ebe441438627a9080bcaa14ce62a8ed101 100644 (file)
--- a/src/pkg/bufio/bufio_test.go
+++ b/src/pkg/bufio/bufio_test.go
@@ -168,6 +168,62 @@ func TestReader(t *testing.T) {
        }
 }
 
+// A StringReader delivers its data one string segment at a time via Read.
+type StringReader struct {
+       data []string;
+       step int;
+}
+
+func (r *StringReader) Read (p []byte) (n int, err os.Error) {
+       if r.step < len(r.data) {
+               s := r.data[r.step];
+               for i := 0; i < len(s); i++ {
+                       p[i] = s[i];
+               }
+               n = len(s);
+               r.step++;
+       } else {
+               err = os.EOF;
+       }
+       return;
+}
+
+func readRuneSegments(t *testing.T, segments []string) {
+       got := "";
+       want := strings.Join(segments, "");
+       r := bufio.NewReader(&StringReader{data: segments});
+       for {
+               rune, size, err := r.ReadRune();
+               if err != nil {
+                       if err != os.EOF {
+                               return;
+                       }
+                       break;
+               }
+               got += string(rune);
+       }
+       if got != want {
+               t.Errorf("segments=%v got=%s want=%s", segments, got, want);
+       }
+}
+
+var segmentList = [][]string {
+       []string{},
+       []string{""},
+       []string{"日", "本語"},
+       []string{"\u65e5", "\u672c", "\u8a9e"},
+       []string{"\U000065e5, "", \U0000672c", "\U00008a9e"},
+       []string{"\xe6", "\x97\xa5\xe6", "\x9c\xac\xe8\xaa\x9e"},
+       []string{"Hello", ", ", "World", "!"},
+       []string{"Hello", ", ", "", "World", "!"},
+}
+
+func TestReadRune(t *testing.T) {
+       for _, s := range segmentList {
+               readRuneSegments(t, s);
+       }
+}
+
 func TestWriter(t *testing.T) {
        var data [8192]byte;