mime: text charset defaults

Enforce + document the UTF-8 default.

R=rsc, bradfitz, adg
CC=golang-dev
https://golang.org/cl/4627049

diff --git a/src/pkg/mime/type.go b/src/pkg/mime/type.go
index 8ecfe9a37b1f3acf05d83d88927231d23e701191..deb0ff6d916bff0cc35a20e5675ce9545b024c5e 100644 (file)
--- a/src/pkg/mime/type.go
+++ b/src/pkg/mime/type.go
@@ -7,6 +7,7 @@ package mime
 
 import (
        "bufio"
+       "fmt"
        "os"
        "strings"
        "sync"
@@ -19,15 +20,15 @@ var typeFiles = []string{
 }
 
 var mimeTypes = map[string]string{
-       ".css":  "text/css; charset=utf-8",
+       ".css":  "text/css;charset=utf-8",
        ".gif":  "image/gif",
-       ".htm":  "text/html; charset=utf-8",
-       ".html": "text/html; charset=utf-8",
+       ".htm":  "text/html;charset=utf-8",
+       ".html": "text/html;charset=utf-8",
        ".jpg":  "image/jpeg",
        ".js":   "application/x-javascript",
        ".pdf":  "application/pdf",
        ".png":  "image/png",
-       ".xml":  "text/xml; charset=utf-8",
+       ".xml":  "text/xml;charset=utf-8",
 }
 
 var mimeLock sync.RWMutex
@@ -49,15 +50,12 @@ func loadMimeFile(filename string) {
                if len(fields) <= 1 || fields[0][0] == '#' {
                        continue
                }
-               typename := fields[0]
-               if strings.HasPrefix(typename, "text/") {
-                       typename += "; charset=utf-8"
-               }
+               mimeType := fields[0]
                for _, ext := range fields[1:] {
                        if ext[0] == '#' {
                                break
                        }
-                       mimeTypes["."+ext] = typename
+                       setExtensionType("."+ext, mimeType)
                }
        }
 }
@@ -81,6 +79,8 @@ var once sync.Once
 //   /etc/mime.types
 //   /etc/apache2/mime.types
 //   /etc/apache/mime.types
+//
+// Text types have the charset parameter set to "utf-8" by default.
 func TypeByExtension(ext string) string {
        once.Do(initMime)
        mimeLock.RLock()
@@ -93,12 +93,31 @@ func TypeByExtension(ext string) string {
 // the extension ext to typ.  The extension should begin with
 // a leading dot, as in ".html".
 func AddExtensionType(ext, typ string) os.Error {
+       if ext == "" || ext[0] != '.' {
+               return fmt.Errorf(`mime: extension "%s" misses dot`, ext)
+       }
        once.Do(initMime)
-       if len(ext) < 1 || ext[0] != '.' {
-               return os.EINVAL
+       return setExtensionType(ext, typ)
+}
+
+func setExtensionType(extension, mimeType string) os.Error {
+       full, param, err := ParseMediaType(mimeType)
+       if err != nil {
+               return err
+       }
+       if split := strings.Index(full, "/"); split < 0 {
+               return fmt.Errorf(`mime: malformed MIME type "%s"`, mimeType)
+       } else {
+               main := full[:split]
+               sub := full[split+1:]
+               if main == "text" && param["charset"] == "" {
+                       param["charset"] = "utf-8"
+               }
+               mimeType = FormatMediaType(main, sub, param)
        }
+
        mimeLock.Lock()
-       mimeTypes[ext] = typ
+       mimeTypes[extension] = mimeType
        mimeLock.Unlock()
        return nil
 }

diff --git a/src/pkg/mime/mime_test.go b/src/pkg/mime/type_test.go
similarity index 53%
rename from src/pkg/mime/mime_test.go
rename to src/pkg/mime/type_test.go
index 17e610443e7490c55fdb7a74c80905ba03566238..2af39c7bb8066eec0d97eb60856f7b747db7abbd 100644 (file)
--- a/src/pkg/mime/mime_test.go
+++ b/src/pkg/mime/type_test.go
@@ -2,19 +2,17 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Tests for type.go
-
 package mime
 
 import "testing"
 
 var typeTests = map[string]string{
        ".t1":  "application/test",
-       ".t2":  "text/test; charset=utf-8",
+       ".t2":  "text/test;charset=utf-8",
        ".png": "image/png",
 }
 
-func TestType(t *testing.T) {
+func TestTypeByExtension(t *testing.T) {
        typeFiles = []string{"test.types"}
 
        for ext, want := range typeTests {
@@ -25,3 +23,13 @@ func TestType(t *testing.T) {
 
        }
 }
+
+func TestCustomExtension(t *testing.T) {
+       custom := "text/xml;charset=iso-8859-1"
+       if error := AddExtensionType(".xml", custom); error != nil {
+               t.Fatalf("error %s for AddExtension(%s)", error, custom)
+       }
+       if registered := TypeByExtension(".xml"); registered != custom {
+               t.Fatalf("registered %s instead of %s", registered, custom)
+       }
+}