Fixed a small bug with compress/flate/Inflater. It incorrectly checked

the size of chunk with uncompressed data (00 is terms of DEFLATE).

APPROVED=rsc
DELTA=15  (14 added, 0 deleted, 1 changed)
OCL=32105
CL=32238

src/pkg/compress/flate/flate_test.go

@@ -9,6 +9,7 @@
 package flate
 
 import (
+	"bytes";
 	"bufio";
 	"compress/flate";
 	"io";
@@ -129,3 +130,16 @@ func TestInitDecoder(t *testing.T) {
 		}
 	}
 }
+
+func TestUncompressedSource(t *testing.T) {
+	decoder := NewInflater(bytes.NewBuffer(
+		[]byte{ 0x01, 0x01, 0x00, 0xfe, 0xff, 0x11 }));
+	output := make([]byte, 1);
+	n, error := decoder.Read(output);
+	if n != 1 || error != nil {
+		t.Fatalf("decoder.Read() = %d, %v, want 1, nil", n, error);
+	}
+	if output[0] != 0x11 {
+		t.Errorf("output[0] = %x, want 0x11", output[0]);
+	}
+}

src/pkg/compress/flate/inflate.go

@@ -542,7 +542,7 @@ func (f *inflater) dataBlock() os.Error {
 	}
 	n := int(f.buf[0]) | int(f.buf[1])<<8;
 	nn := int(f.buf[2]) | int(f.buf[3])<<8;
-	if nn != ^n {
+	if uint16(nn) != uint16(^n) {
 		return CorruptInputError(f.roffset);
 	}