From ff85932af903df83d21e6394ab408863ccf4a845 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Mon, 25 Feb 2019 16:00:14 -0700
Subject: [PATCH 1/2] cli: fix ignoring std{out,err} sync errors on windows

Apparently, windows returns "invalid file handle" and golang doesn't translate
this to EINVAL.

fixes ipfs/go-ipfs#6021
---
 cli/error.go           | 13 +++++++++++++
 cli/error_posix.go     | 15 +++++++++++++++
 cli/error_windows.go   | 17 +++++++++++++++++
 cli/responseemitter.go | 18 ++++--------------
 4 files changed, 49 insertions(+), 14 deletions(-)
 create mode 100644 cli/error.go
 create mode 100644 cli/error_posix.go
 create mode 100644 cli/error_windows.go

diff --git a/cli/error.go b/cli/error.go
new file mode 100644
index 00000000..92fe7278
--- /dev/null
+++ b/cli/error.go
@@ -0,0 +1,13 @@
+package cli
+
+import (
+	"os"
+)
+
+func isSyncNotSupportedErr(err error) bool {
+	perr, ok := err.(*os.PathError)
+	if !ok {
+		return false
+	}
+	return perr.Op == "sync" && isErrnoNotSupported(perr.Err)
+}
diff --git a/cli/error_posix.go b/cli/error_posix.go
new file mode 100644
index 00000000..f9d52a3a
--- /dev/null
+++ b/cli/error_posix.go
@@ -0,0 +1,15 @@
+//+build !windows
+
+package cli
+
+import (
+	"syscall"
+)
+
+func isErrnoNotSupported(err error) bool {
+	switch err {
+	case syscall.EINVAL, syscall.ENOTSUP:
+		return true
+	}
+	return false
+}
diff --git a/cli/error_windows.go b/cli/error_windows.go
new file mode 100644
index 00000000..0c882846
--- /dev/null
+++ b/cli/error_windows.go
@@ -0,0 +1,17 @@
+//+build windows
+
+package cli
+
+import (
+	"syscall"
+)
+
+const invalid_file_handle syscall.Errno = 0x6
+
+func isErrnoNotSupported(err error) bool {
+	switch err {
+	case syscall.EINVAL, syscall.ENOTSUP, invalid_file_handle:
+		return true
+	}
+	return false
+}
diff --git a/cli/responseemitter.go b/cli/responseemitter.go
index 6b882f04..86c98f09 100644
--- a/cli/responseemitter.go
+++ b/cli/responseemitter.go
@@ -6,7 +6,6 @@ import (
 	"io"
 	"os"
 	"sync"
-	"syscall"
 
 	"github.com/ipfs/go-ipfs-cmds"
 )
@@ -101,17 +100,6 @@ func (re *responseEmitter) CloseWithError(err error) error {
 		re.stderr = nil
 	}()
 
-	// ignore error if the operating system doesn't support syncing std{out,err}
-	ignoreError := func(err error) bool {
-		if perr, ok := err.(*os.PathError); ok &&
-			perr.Op == "sync" && (perr.Err == syscall.EINVAL ||
-			perr.Err == syscall.ENOTSUP) {
-			return true
-		}
-
-		return false
-	}
-
 	var errStderr, errStdout error
 	if f, ok := re.stderr.(*os.File); ok {
 		errStderr = f.Sync()
@@ -119,10 +107,12 @@ func (re *responseEmitter) CloseWithError(err error) error {
 	if f, ok := re.stdout.(*os.File); ok {
 		errStdout = f.Sync()
 	}
-	if errStderr != nil && !ignoreError(errStderr) {
+
+	// ignore error if the operating system doesn't support syncing std{out,err}
+	if errStderr != nil && !isSyncNotSupportedErr(errStderr) {
 		return errStderr
 	}
-	if errStdout != nil && !ignoreError(errStdout) {
+	if errStdout != nil && !isSyncNotSupportedErr(errStdout) {
 		return errStdout
 	}
 	return nil

From 9d994fb30ce9a3a3c0d192613a967f38395840a2 Mon Sep 17 00:00:00 2001
From: Steven Allen <steven@stebalien.com>
Date: Mon, 25 Feb 2019 16:03:21 -0700
Subject: [PATCH 2/2] docs: document cli.NewResponseEmitter

---
 cli/responseemitter.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/cli/responseemitter.go b/cli/responseemitter.go
index 86c98f09..db46a907 100644
--- a/cli/responseemitter.go
+++ b/cli/responseemitter.go
@@ -12,6 +12,8 @@ import (
 
 var _ ResponseEmitter = &responseEmitter{}
 
+// NewResponseEmitter constructs a new response emitter that writes results to
+// the console.
 func NewResponseEmitter(stdout, stderr io.Writer, req *cmds.Request) (ResponseEmitter, error) {
 	encType, enc, err := cmds.GetEncoder(req, stdout, cmds.TextNewline)