1 files changed, 41 insertions, 23 deletions

diff --git a/vendor/github.com/lib/pq/conn_go18.go b/vendor/github.com/lib/pq/conn_go18.go
index 43cc35f7b..fa3755d99 100644
--- a/vendor/github.com/lib/pq/conn_go18.go
+++ b/vendor/github.com/lib/pq/conn_go18.go
@@ -6,6 +6,8 @@ import (
 	"context"
 	"database/sql/driver"
 	"errors"
+	"io"
+	"io/ioutil"
 )
 
 // Implement the "QueryerContext" interface
@@ -14,12 +16,12 @@ func (cn *conn) QueryContext(ctx context.Context, query string, args []driver.Na
 	for i, nv := range args {
 		list[i] = nv.Value
 	}
-	closed := cn.watchCancel(ctx)
+	finish := cn.watchCancel(ctx)
 	r, err := cn.query(query, list)
 	if err != nil {
 		return nil, err
 	}
-	r.closed = closed
+	r.finish = finish
 	return r, nil
 }
 
@@ -30,8 +32,8 @@ func (cn *conn) ExecContext(ctx context.Context, query string, args []driver.Nam
 		list[i] = nv.Value
 	}
 
-	if closed := cn.watchCancel(ctx); closed != nil {
-		defer close(closed)
+	if finish := cn.watchCancel(ctx); finish != nil {
+		defer finish()
 	}
 
 	return cn.Exec(query, list)
@@ -49,41 +51,57 @@ func (cn *conn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver.Tx,
 	if err != nil {
 		return nil, err
 	}
-	cn.txnClosed = cn.watchCancel(ctx)
+	cn.txnFinish = cn.watchCancel(ctx)
 	return tx, nil
 }
 
-func (cn *conn) watchCancel(ctx context.Context) chan<- struct{} {
+func (cn *conn) watchCancel(ctx context.Context) func() {
 	if done := ctx.Done(); done != nil {
-		closed := make(chan struct{})
+		finished := make(chan struct{})
 		go func() {
 			select {
 			case <-done:
-				cn.cancel()
-			case <-closed:
+				_ = cn.cancel()
+				finished <- struct{}{}
+			case <-finished:
 			}
 		}()
-		return closed
+		return func() {
+			select {
+			case <-finished:
+			case finished <- struct{}{}:
+			}
+		}
 	}
 	return nil
 }
 
-func (cn *conn) cancel() {
-	var err error
-	can := &conn{}
-	can.c, err = dial(cn.dialer, cn.opts)
+func (cn *conn) cancel() error {
+	c, err := dial(cn.dialer, cn.opts)
 	if err != nil {
-		return
+		return err
 	}
-	can.ssl(cn.opts)
+	defer c.Close()
 
-	defer can.errRecover(&err)
+	{
+		can := conn{
+			c: c,
+		}
+		can.ssl(cn.opts)
 
-	w := can.writeBuf(0)
-	w.int32(80877102) // cancel request code
-	w.int32(cn.processID)
-	w.int32(cn.secretKey)
+		w := can.writeBuf(0)
+		w.int32(80877102) // cancel request code
+		w.int32(cn.processID)
+		w.int32(cn.secretKey)
 
-	can.sendStartupPacket(w)
-	_ = can.c.Close()
+		if err := can.sendStartupPacket(w); err != nil {
+			return err
+		}
+	}
+
+	// Read until EOF to ensure that the server received the cancel.
+	{
+		_, err := io.Copy(ioutil.Discard, c)
+		return err
+	}
 }