[release-branch.go1.2] encoding/gob: do not use MarshalText, UnmarshalText
««« CL 22770044 / 23fc3139589c
encoding/gob: do not use MarshalText, UnmarshalText
This seems to be the best of a long list of bad ways to fix this issue.
Fixes #6760.
R=r
CC=golang-dev
https://golang.org/cl/22770044
»»»
R=golang-dev
CC=golang-dev
https://golang.org/cl/28110043
diff --git a/doc/go1.2.html b/doc/go1.2.html
index 9d890b2..c7a9f84 100644
--- a/doc/go1.2.html
+++ b/doc/go1.2.html
@@ -736,7 +736,8 @@
even if they are not. That is, it ignores them completely. Previously they would
trigger an error, which could cause unexpected compatibility problems if an
embedded structure added such a field.
-The package also now supports the generic encoding interfaces of the
+The package also now supports the generic <code>BinaryMarshaler</code> and
+<code>BinaryUnmarshaler</code> interfaces of the
<a href="/pkg/encoding/"><code>encoding</code></a> package
described above.
</li>
diff --git a/src/pkg/encoding/gob/doc.go b/src/pkg/encoding/gob/doc.go
index 28f0c05..d0acaba 100644
--- a/src/pkg/encoding/gob/doc.go
+++ b/src/pkg/encoding/gob/doc.go
@@ -86,13 +86,13 @@
at top the level will fail. A struct field of chan or func type is treated exactly
like an unexported field and is ignored.
-Gob can encode a value of any type implementing the GobEncoder,
-encoding.BinaryMarshaler, or encoding.TextMarshaler interfaces by calling the
-corresponding method, in that order of preference.
+Gob can encode a value of any type implementing the GobEncoder or
+encoding.BinaryMarshaler interfaces by calling the corresponding method,
+in that order of preference.
-Gob can decode a value of any type implementing the GobDecoder,
-encoding.BinaryUnmarshaler, or encoding.TextUnmarshaler interfaces by calling
-the corresponding method, again in that order of preference.
+Gob can decode a value of any type implementing the GobDecoder or
+encoding.BinaryUnmarshaler interfaces by calling the corresponding method,
+again in that order of preference.
Encoding Details
diff --git a/src/pkg/encoding/gob/gobencdec_test.go b/src/pkg/encoding/gob/gobencdec_test.go
index 301551d..0193e2b 100644
--- a/src/pkg/encoding/gob/gobencdec_test.go
+++ b/src/pkg/encoding/gob/gobencdec_test.go
@@ -11,6 +11,7 @@
"errors"
"fmt"
"io"
+ "net"
"strings"
"testing"
"time"
@@ -767,3 +768,17 @@
t.Fatalf("expected nil, got %v", err2)
}
}
+
+func TestNetIP(t *testing.T) {
+ // Encoding of net.IP{1,2,3,4} in Go 1.1.
+ enc := []byte{0x07, 0x0a, 0x00, 0x04, 0x01, 0x02, 0x03, 0x04}
+
+ var ip net.IP
+ err := NewDecoder(bytes.NewReader(enc)).Decode(&ip)
+ if err != nil {
+ t.Fatalf("decode: %v", err)
+ }
+ if ip.String() != "1.2.3.4" {
+ t.Errorf("decoded to %v, want 1.2.3.4", ip.String())
+ }
+}
diff --git a/src/pkg/encoding/gob/type.go b/src/pkg/encoding/gob/type.go
index 65bf17b..cad1452 100644
--- a/src/pkg/encoding/gob/type.go
+++ b/src/pkg/encoding/gob/type.go
@@ -88,18 +88,25 @@
ut.externalEnc, ut.encIndir = xGob, indir
} else if ok, indir := implementsInterface(ut.user, binaryMarshalerInterfaceType); ok {
ut.externalEnc, ut.encIndir = xBinary, indir
- } else if ok, indir := implementsInterface(ut.user, textMarshalerInterfaceType); ok {
- ut.externalEnc, ut.encIndir = xText, indir
}
+ // NOTE(rsc): Would like to allow MarshalText here, but results in incompatibility
+ // with older encodings for net.IP. See golang.org/issue/6760.
+ // } else if ok, indir := implementsInterface(ut.user, textMarshalerInterfaceType); ok {
+ // ut.externalEnc, ut.encIndir = xText, indir
+ // }
+
if ok, indir := implementsInterface(ut.user, gobDecoderInterfaceType); ok {
ut.externalDec, ut.decIndir = xGob, indir
} else if ok, indir := implementsInterface(ut.user, binaryUnmarshalerInterfaceType); ok {
ut.externalDec, ut.decIndir = xBinary, indir
- } else if ok, indir := implementsInterface(ut.user, textUnmarshalerInterfaceType); ok {
- ut.externalDec, ut.decIndir = xText, indir
}
+ // See note above.
+ // } else if ok, indir := implementsInterface(ut.user, textUnmarshalerInterfaceType); ok {
+ // ut.externalDec, ut.decIndir = xText, indir
+ // }
+
userTypeCache[rt] = ut
return
}
