http: parse query string always, not just in GET

Fixes #985.

R=dsymonds, dsymonds1
CC=golang-dev
https://golang.org/cl/1963044

src/pkg/http/request.go

@@ -588,9 +588,22 @@ func ReadRequest(b *bufio.Reader) (req *Request, err os.Error) {
 	return req, nil
 }
 
+// ParseQuery parses the URL-encoded query string and returns
+// a map listing the values specified for each key.
+// ParseQuery always returns a non-nil map containing all the
+// valid query parameters found; err describes the first decoding error
+// encountered, if any.
 func ParseQuery(query string) (m map[string][]string, err os.Error) {
 	m = make(map[string][]string)
+	err = parseQuery(m, query)
+	return
+}
+
+func parseQuery(m map[string][]string, query string) (err os.Error) {
 	for _, kv := range strings.Split(query, "&", -1) {
+		if len(kv) == 0 {
+			continue
+		}
 		kvPair := strings.Split(kv, "=", 2)
 
 		var key, value string
@@ -601,14 +614,13 @@ func ParseQuery(query string) (m map[string][]string, err os.Error) {
 		}
 		if e != nil {
 			err = e
+			continue
 		}
-
 		vec := vector.StringVector(m[key])
 		vec.Push(value)
 		m[key] = vec
 	}
-
-	return
+	return err
 }
 
 // ParseForm parses the request body as a form for POST requests, or the raw query for GET requests.
@@ -618,32 +630,34 @@ func (r *Request) ParseForm() (err os.Error) {
 		return
 	}
 
-	var query string
-	switch r.Method {
-	case "GET":
-		query = r.URL.RawQuery
-	case "POST":
+	r.Form = make(map[string][]string)
+	if r.URL != nil {
+		err = parseQuery(r.Form, r.URL.RawQuery)
+	}
+	if r.Method == "POST" {
 		if r.Body == nil {
-			r.Form = make(map[string][]string)
 			return os.ErrorString("missing form body")
 		}
 		ct := r.Header["Content-Type"]
 		switch strings.Split(ct, ";", 2)[0] {
 		case "text/plain", "application/x-www-form-urlencoded", "":
-			var b []byte
-			if b, err = ioutil.ReadAll(r.Body); err != nil {
-				r.Form = make(map[string][]string)
-				return err
+			b, e := ioutil.ReadAll(r.Body)
+			if e != nil {
+				if err == nil {
+					err = e
+				}
+				break
+			}
+			e = parseQuery(r.Form, string(b))
+			if err == nil {
+				err = e
 			}
-			query = string(b)
 		// TODO(dsymonds): Handle multipart/form-data
 		default:
-			r.Form = make(map[string][]string)
 			return &badStringError{"unknown Content-Type", ct}
 		}
 	}
-	r.Form, err = ParseQuery(query)
-	return
+	return err
 }
 
 // FormValue returns the first value for the named component of the query.

src/pkg/http/request_test.go

@@ -6,6 +6,8 @@ package http
 
 import (
 	"bytes"
+	"reflect"
+	"strings"
 	"testing"
 )
 
@@ -68,6 +70,22 @@ func TestQuery(t *testing.T) {
 	}
 }
 
+func TestPostQuery(t *testing.T) {
+	req := &Request{Method: "POST"}
+	req.URL, _ = ParseURL("http://www.google.com/search?q=foo&q=bar&both=x")
+	req.Header = map[string]string{"Content-Type": "application/x-www-form-urlencoded; boo!"}
+	req.Body = nopCloser{strings.NewReader("z=post&both=y")}
+	if q := req.FormValue("q"); q != "foo" {
+		t.Errorf(`req.FormValue("q") = %q, want "foo"`, q)
+	}
+	if z := req.FormValue("z"); z != "post" {
+		t.Errorf(`req.FormValue("z") = %q, want "post"`, z)
+	}
+	if both := req.Form["both"]; !reflect.DeepEqual(both, []string{"x", "y"}) {
+		t.Errorf(`req.FormValue("both") = %q, want ["x", "y"]`, both)
+	}
+}
+
 type stringMap map[string]string
 type parseContentTypeTest struct {
 	contentType stringMap