Fix for #1874

Created subprocess.Cmd wrapper to autoclose any created pipes
Removing original fix for #1860

git/git.go

@@ -445,10 +445,7 @@ func RecentBranches(since time.Time, includeRemoteBranches bool, onlyRemote stri
 		return nil, fmt.Errorf("Failed to call git for-each-ref: %v", err)
 	}
 	cmd.Start()
-	defer func() {
-		outp.Close()
-		cmd.Wait()
-	}()
+	defer cmd.Wait()
 
 	scanner := bufio.NewScanner(outp)
 

subprocess/cmd.go

@@ -0,0 +1,46 @@
+package subprocess
+
+import (
+	"io"
+	"os/exec"
+)
+
+// Thin wrapper around exec.Cmd. Takes care of pipe shutdown by
+// keeping an internal reference to any created pipes. Whenever
+// Cmd.Wait() is called, all created pipes are closed.
+type Cmd struct {
+	*exec.Cmd
+
+	pipes []io.Closer
+}
+
+func (c *Cmd) StdoutPipe() (io.ReadCloser, error) {
+	stdout, err := c.Cmd.StdoutPipe()
+	c.pipes = append(c.pipes, stdout)
+	return stdout, err
+}
+
+func (c *Cmd) StderrPipe() (io.ReadCloser, error) {
+	stderr, err := c.Cmd.StderrPipe()
+	c.pipes = append(c.pipes, stderr)
+	return stderr, err
+}
+
+func (c *Cmd) StdinPipe() (io.WriteCloser, error) {
+	stdin, err := c.Cmd.StdinPipe()
+	c.pipes = append(c.pipes, stdin)
+	return stdin, err
+}
+
+func (c *Cmd) Wait() error {
+	for _, pipe := range c.pipes {
+		pipe.Close()
+	}
+
+	return c.Cmd.Wait()
+}
+
+func newCmd(cmd *exec.Cmd) *Cmd {
+	wrapped := &Cmd{Cmd: cmd}
+	return wrapped
+}

subprocess/subprocess_nix.go

@@ -7,8 +7,8 @@ import (
 )
 
 // ExecCommand is a small platform specific wrapper around os/exec.Command
-func ExecCommand(name string, arg ...string) *exec.Cmd {
+func ExecCommand(name string, arg ...string) *Cmd {
 	cmd := exec.Command(name, arg...)
 	cmd.Env = env
-	return cmd
+	return newCmd(cmd)
 }

subprocess/subprocess_windows.go

@@ -8,9 +8,9 @@ import (
 )
 
 // ExecCommand is a small platform specific wrapper around os/exec.Command
-func ExecCommand(name string, arg ...string) *exec.Cmd {
+func ExecCommand(name string, arg ...string) *Cmd {
 	cmd := exec.Command(name, arg...)
 	cmd.SysProcAttr = &syscall.SysProcAttr{HideWindow: true}
 	cmd.Env = env
-	return cmd
+	return newCmd(cmd)
 }

tq/custom.go

@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"os/exec"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -52,7 +51,7 @@ func (t *traceWriter) Flush() {
 
 type customAdapterWorkerContext struct {
 	workerNum   int
-	cmd         *exec.Cmd
+	cmd         *subprocess.Cmd
 	stdout      io.ReadCloser
 	bufferedOut *bufio.Reader
 	stdin       io.WriteCloser
@@ -70,7 +69,8 @@ func NewCustomAdapterInitRequest(op string, concurrent bool, concurrentTransfers
 	return &customAdapterInitRequest{"init", op, concurrent, concurrentTransfers}
 }
 
-type customAdapterTransferRequest struct { // common between upload/download
+type customAdapterTransferRequest struct {
+	// common between upload/download
 	Event  string  `json:"event"`
 	Oid    string  `json:"oid"`
 	Size   int64   `json:"size"`