all: import "context" instead of "golang.org/x/net/context"

There is no need to depend on the old context package now that the
minimum Go version is 1.7. The move to "context" eliminates our weird
vendoring setup. Some vendored code still uses golang.org/x/net/context
and it is now vendored in the normal way.

This change triggered new vet checks around context.WithTimeout which
didn't fire with golang.org/x/net/context.

5 files changed, 14 insertions, 9 deletions

diff --git a/les/api_backend.go b/les/api_backend.go
index 006240369..df2782f78 100644
--- a/les/api_backend.go
+++ b/les/api_backend.go
@@ -17,6 +17,7 @@
 package les
 
 import (
+	"context"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/accounts"
@@ -33,7 +34,6 @@ import (
 	"github.com/ethereum/go-ethereum/light"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
-	"golang.org/x/net/context"
 )
 
 type LesApiBackend struct {
diff --git a/les/odr.go b/les/odr.go
index 06b44d318..684f36c76 100644
--- a/les/odr.go
+++ b/les/odr.go
@@ -17,6 +17,7 @@
 package les
 
 import (
+	"context"
 	"crypto/rand"
 	"encoding/binary"
 	"sync"
@@ -26,7 +27,6 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/light"
 	"github.com/ethereum/go-ethereum/log"
-	"golang.org/x/net/context"
 )
 
 var (
diff --git a/les/odr_test.go b/les/odr_test.go
index 1b436b8e6..6b074f1a2 100644
--- a/les/odr_test.go
+++ b/les/odr_test.go
@@ -18,6 +18,7 @@ package les
 
 import (
 	"bytes"
+	"context"
 	"math/big"
 	"testing"
 	"time"
@@ -32,7 +33,6 @@ import (
 	"github.com/ethereum/go-ethereum/light"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
-	"golang.org/x/net/context"
 )
 
 type odrTestFn func(ctx context.Context, db ethdb.Database, config *params.ChainConfig, bc *core.BlockChain, lc *light.LightChain, bhash common.Hash) []byte
@@ -181,8 +181,11 @@ func testOdr(t *testing.T, protocol int, expFail uint64, fn odrTestFn) {
 		for i := uint64(0); i <= pm.blockchain.CurrentHeader().Number.Uint64(); i++ {
 			bhash := core.GetCanonicalHash(db, i)
 			b1 := fn(light.NoOdr, db, pm.chainConfig, pm.blockchain.(*core.BlockChain), nil, bhash)
-			ctx, _ := context.WithTimeout(context.Background(), 200*time.Millisecond)
+
+			ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
+			defer cancel()
 			b2 := fn(ctx, ldb, lpm.chainConfig, nil, lpm.blockchain.(*light.LightChain), bhash)
+
 			eq := bytes.Equal(b1, b2)
 			exp := i < expFail
 			if exp && !eq {
diff --git a/les/request_test.go b/les/request_test.go
index bec6bf1bc..ba1fc15bd 100644
--- a/les/request_test.go
+++ b/les/request_test.go
@@ -17,6 +17,7 @@
 package les
 
 import (
+	"context"
 	"testing"
 	"time"
 
@@ -25,7 +26,6 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/light"
-	"golang.org/x/net/context"
 )
 
 var testBankSecureTrieKey = secAddr(testBankAddress)
@@ -91,7 +91,9 @@ func testAccess(t *testing.T, protocol int, fn accessTestFn) {
 		for i := uint64(0); i <= pm.blockchain.CurrentHeader().Number.Uint64(); i++ {
 			bhash := core.GetCanonicalHash(db, i)
 			if req := fn(ldb, bhash, i); req != nil {
-				ctx, _ := context.WithTimeout(context.Background(), 200*time.Millisecond)
+				ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
+				defer cancel()
+
 				err := odr.Retrieve(ctx, req)
 				got := err == nil
 				exp := i < expFail
diff --git a/les/sync.go b/les/sync.go
index c143cb145..c0e17f97d 100644
--- a/les/sync.go
+++ b/les/sync.go
@@ -17,12 +17,12 @@
 package les
 
 import (
+	"context"
 	"time"
 
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/eth/downloader"
 	"github.com/ethereum/go-ethereum/light"
-	"golang.org/x/net/context"
 )
 
 const (
@@ -77,8 +77,8 @@ func (pm *ProtocolManager) synchronise(peer *peer) {
 		return
 	}
 
-	ctx, _ := context.WithTimeout(context.Background(), time.Second*5)
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+	defer cancel()
 	pm.blockchain.(*light.LightChain).SyncCht(ctx)
-
 	pm.downloader.Synchronise(peer.id, peer.Head(), peer.Td(), downloader.LightSync)
 }