migrate to go modules from vndr

Signed-off-by: Tariq Ibrahim <tariq181290@gmail.com>

vendor/golang.org/x/net/http2/pipe.go

@@ -10,13 +10,13 @@ import (
 	"sync"
 )
 
-// pipe is a goroutine-safe io.Reader/io.Writer pair.  It's like
+// pipe is a goroutine-safe io.Reader/io.Writer pair. It's like
 // io.Pipe except there are no PipeReader/PipeWriter halves, and the
 // underlying buffer is an interface. (io.Pipe is always unbuffered)
 type pipe struct {
 	mu       sync.Mutex
-	c        sync.Cond // c.L lazily initialized to &p.mu
-	b        pipeBuffer
+	c        sync.Cond     // c.L lazily initialized to &p.mu
+	b        pipeBuffer    // nil when done reading
 	err      error         // read error once empty. non-nil means closed.
 	breakErr error         // immediate read error (caller doesn't see rest of b)
 	donec    chan struct{} // closed on error
@@ -29,6 +29,15 @@ type pipeBuffer interface {
 	io.Reader
 }
 
+func (p *pipe) Len() int {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.b == nil {
+		return 0
+	}
+	return p.b.Len()
+}
+
 // Read waits until data is available and copies bytes
 // from the buffer into p.
 func (p *pipe) Read(d []byte) (n int, err error) {
@@ -41,7 +50,7 @@ func (p *pipe) Read(d []byte) (n int, err error) {
 		if p.breakErr != nil {
 			return 0, p.breakErr
 		}
-		if p.b.Len() > 0 {
+		if p.b != nil && p.b.Len() > 0 {
 			return p.b.Read(d)
 		}
 		if p.err != nil {
@@ -49,6 +58,7 @@ func (p *pipe) Read(d []byte) (n int, err error) {
 				p.readFn()     // e.g. copy trailers
 				p.readFn = nil // not sticky like p.err
 			}
+			p.b = nil
 			return 0, p.err
 		}
 		p.c.Wait()
@@ -69,6 +79,9 @@ func (p *pipe) Write(d []byte) (n int, err error) {
 	if p.err != nil {
 		return 0, errClosedPipeWrite
 	}
+	if p.breakErr != nil {
+		return len(d), nil // discard when there is no reader
+	}
 	return p.b.Write(d)
 }
 
@@ -103,6 +116,9 @@ func (p *pipe) closeWithError(dst *error, err error, fn func()) {
 		return
 	}
 	p.readFn = fn
+	if dst == &p.breakErr {
+		p.b = nil
+	}
 	*dst = err
 	p.closeDoneLocked()
 }