x/crypto/ssh/terminal: replace \n with \r\n.
18e6eb769a6 made MakeRaw match C's behaviour. This included clearing the
OPOST flag, which means that one now needs to write \r\n for a newline,
otherwise the cursor doesn't move back to the beginning and the terminal
prints a staircase.
(Dear god, we're still emulating line printers.)
This change causes the terminal package to do the required
transformation.
Fixes golang/go#17364.
Change-Id: Ida15d3cf701a21eaa59161ab61b3ed4dee2ded46
Reviewed-on: https://go-review.googlesource.com/33902
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/terminal.go b/terminal.go
index 741eeb1..5ea89a2 100644
--- a/terminal.go
+++ b/terminal.go
@@ -132,8 +132,11 @@
keyPasteEnd
)
-var pasteStart = []byte{keyEscape, '[', '2', '0', '0', '~'}
-var pasteEnd = []byte{keyEscape, '[', '2', '0', '1', '~'}
+var (
+ crlf = []byte{'\r', '\n'}
+ pasteStart = []byte{keyEscape, '[', '2', '0', '0', '~'}
+ pasteEnd = []byte{keyEscape, '[', '2', '0', '1', '~'}
+)
// bytesToKey tries to parse a key sequence from b. If successful, it returns
// the key and the remainder of the input. Otherwise it returns utf8.RuneError.
@@ -333,7 +336,7 @@
// So, if we are stopping at the end of a line, we
// need to write a newline so that our cursor can be
// advanced to the next line.
- t.outBuf = append(t.outBuf, '\n')
+ t.outBuf = append(t.outBuf, '\r', '\n')
}
}
@@ -593,6 +596,35 @@
}
}
+// writeWithCRLF writes buf to w but replaces all occurances of \n with \r\n.
+func writeWithCRLF(w io.Writer, buf []byte) (n int, err error) {
+ for len(buf) > 0 {
+ i := bytes.IndexByte(buf, '\n')
+ todo := len(buf)
+ if i >= 0 {
+ todo = i
+ }
+
+ var nn int
+ nn, err = w.Write(buf[:todo])
+ n += nn
+ if err != nil {
+ return n, err
+ }
+ buf = buf[todo:]
+
+ if i >= 0 {
+ if _, err = w.Write(crlf); err != nil {
+ return n, err
+ }
+ n += 1
+ buf = buf[1:]
+ }
+ }
+
+ return n, nil
+}
+
func (t *Terminal) Write(buf []byte) (n int, err error) {
t.lock.Lock()
defer t.lock.Unlock()
@@ -600,7 +632,7 @@
if t.cursorX == 0 && t.cursorY == 0 {
// This is the easy case: there's nothing on the screen that we
// have to move out of the way.
- return t.c.Write(buf)
+ return writeWithCRLF(t.c, buf)
}
// We have a prompt and possibly user input on the screen. We
@@ -620,7 +652,7 @@
}
t.outBuf = t.outBuf[:0]
- if n, err = t.c.Write(buf); err != nil {
+ if n, err = writeWithCRLF(t.c, buf); err != nil {
return
}
diff --git a/terminal_test.go b/terminal_test.go
index 6bdefb4..1d54c4f 100644
--- a/terminal_test.go
+++ b/terminal_test.go
@@ -5,6 +5,7 @@
package terminal
import (
+ "bytes"
"io"
"os"
"testing"
@@ -289,3 +290,17 @@
t.Errorf("states do not match; was %v, expected %v", raw, st)
}
}
+
+func TestOutputNewlines(t *testing.T) {
+ // \n should be changed to \r\n in terminal output.
+ buf := new(bytes.Buffer)
+ term := NewTerminal(buf, ">")
+
+ term.Write([]byte("1\n2\n"))
+ output := string(buf.Bytes())
+ const expected = "1\r\n2\r\n"
+
+ if output != expected {
+ t.Errorf("incorrect output: was %q, expected %q", output, expected)
+ }
+}
