From 39899e40bf1e0186319a614a13d2c8153e5d336d Mon Sep 17 00:00:00 2001
From: Jakob Borg <jakob@nym.se>
Date: Fri, 6 May 2016 22:01:56 +0000
Subject: [PATCH] cmd/syncthing: Use ReadAll + json.Unmarshal in places were we
 care about consuming the reader

Because json.NewDecoder(r).Decode(&v) doesn't necessarily consume all
data on the reader, that means an HTTP connection can't be reused. We
don't do a lot of HTTP traffic where we read JSON responses, but the
discovery is one such place. The other two are for POSTs from the GUI,
where it's not exactly critical but still nice if the connection still
can be keep-alive'd after the request as well.

Also ensure that we call req.Body.Close() for clarity, even though this
should by all accounts not really be necessary.

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3050
---
 cmd/syncthing/gui.go   | 10 ++++++++--
 lib/config/config.go   |  8 +++++++-
 lib/discover/global.go | 10 ++++++++--
 3 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/cmd/syncthing/gui.go b/cmd/syncthing/gui.go
index 3ae5537d9..17bd7958d 100644
--- a/cmd/syncthing/gui.go
+++ b/cmd/syncthing/gui.go
@@ -718,6 +718,7 @@ func (s *apiService) postSystemConfig(w http.ResponseWriter, r *http.Request) {
 	defer s.systemConfigMut.Unlock()
 
 	to, err := config.ReadJSON(r.Body, myID)
+	r.Body.Close()
 	if err != nil {
 		l.Warnln("decoding posted config:", err)
 		http.Error(w, err.Error(), http.StatusBadRequest)
@@ -940,10 +941,15 @@ func (s *apiService) getDBIgnores(w http.ResponseWriter, r *http.Request) {
 func (s *apiService) postDBIgnores(w http.ResponseWriter, r *http.Request) {
 	qs := r.URL.Query()
 
-	var data map[string][]string
-	err := json.NewDecoder(r.Body).Decode(&data)
+	bs, err := ioutil.ReadAll(r.Body)
 	r.Body.Close()
+	if err != nil {
+		http.Error(w, err.Error(), 500)
+		return
+	}
 
+	var data map[string][]string
+	err = json.Unmarshal(bs, &data)
 	if err != nil {
 		http.Error(w, err.Error(), 500)
 		return
diff --git a/lib/config/config.go b/lib/config/config.go
index d981d83e7..b179e9216 100644
--- a/lib/config/config.go
+++ b/lib/config/config.go
@@ -11,6 +11,7 @@ import (
 	"encoding/json"
 	"encoding/xml"
 	"io"
+	"io/ioutil"
 	"net/url"
 	"os"
 	"sort"
@@ -92,7 +93,12 @@ func ReadJSON(r io.Reader, myID protocol.DeviceID) (Configuration, error) {
 	util.SetDefaults(&cfg.Options)
 	util.SetDefaults(&cfg.GUI)
 
-	err := json.NewDecoder(r).Decode(&cfg)
+	bs, err := ioutil.ReadAll(r)
+	if err != nil {
+		return cfg, err
+	}
+
+	err = json.Unmarshal(bs, &cfg)
 	cfg.OriginalVersion = cfg.Version
 
 	cfg.prepare(myID)
diff --git a/lib/discover/global.go b/lib/discover/global.go
index 22a85b78e..aa1dafe5b 100644
--- a/lib/discover/global.go
+++ b/lib/discover/global.go
@@ -12,6 +12,7 @@ import (
 	"encoding/json"
 	"errors"
 	"io"
+	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -154,9 +155,14 @@ func (c *globalClient) Lookup(device protocol.DeviceID) (addresses []string, err
 		return nil, err
 	}
 
-	var ann announcement
-	err = json.NewDecoder(resp.Body).Decode(&ann)
+	bs, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
 	resp.Body.Close()
+
+	var ann announcement
+	err = json.Unmarshal(bs, &ann)
 	return ann.Addresses, err
 }