Make exp/draw/x11 respect $XAUTHORITY.

R=rsc, cw, nigeltao_golang
CC=golang-dev
https://golang.org/cl/1134041

diff --git a/src/pkg/exp/draw/x11/auth.go b/src/pkg/exp/draw/x11/auth.go
index 82dd58c28a497a273ed4cb3e2c9669121d377aa3..7e6ede3ebb406bf134a9e2ee59f983a4fce6ea91 100644 (file)
--- a/src/pkg/exp/draw/x11/auth.go
+++ b/src/pkg/exp/draw/x11/auth.go
@@ -10,7 +10,7 @@ import (
        "os"
 )
 
-// Reads the DISPLAY environment variable, and returns the "12" in ":12.0".
+// getDisplay reads the DISPLAY environment variable, and returns the "12" in ":12.0".
 func getDisplay() string {
        d := os.Getenv("DISPLAY")
        if len(d) < 1 || d[0] != ':' {
@@ -25,7 +25,7 @@ func getDisplay() string {
        return d[1:i]
 }
 
-// Reads a big-endian uint16 from r, using b as a scratch buffer.
+// readU16BE reads a big-endian uint16 from r, using b as a scratch buffer.
 func readU16BE(r io.Reader, b []byte) (uint16, os.Error) {
        _, err := io.ReadFull(r, b[0:2])
        if err != nil {
@@ -34,34 +34,38 @@ func readU16BE(r io.Reader, b []byte) (uint16, os.Error) {
        return uint16(b[0])<<8 + uint16(b[1]), nil
 }
 
-// Reads a length-prefixed string from r, using b as a scratch buffer.
-func readStr(r io.Reader, b []byte) (s string, err os.Error) {
+// readStr reads a length-prefixed string from r, using b as a scratch buffer.
+func readStr(r io.Reader, b []byte) (string, os.Error) {
        n, err := readU16BE(r, b)
        if err != nil {
-               return
+               return "", err
        }
        if int(n) > len(b) {
-               return s, os.NewError("Xauthority entry too long for buffer")
+               return "", os.NewError("Xauthority entry too long for buffer")
        }
        _, err = io.ReadFull(r, b[0:n])
        if err != nil {
-               return
+               return "", err
        }
        return string(b[0:n]), nil
 }
 
-// Reads the ~/.Xauthority file and returns the name/data pair for the DISPLAY.
+// readAuth reads the X authority file and returns the name/data pair for the DISPLAY.
 // b is a scratch buffer to use, and should be at least 256 bytes long (i.e. it should be able to hold a hostname).
 func readAuth(b []byte) (name, data string, err os.Error) {
        // As per /usr/include/X11/Xauth.h.
        const familyLocal = 256
 
-       home := os.Getenv("HOME")
-       if len(home) == 0 {
-               err = os.NewError("unknown HOME")
-               return
+       fn := os.Getenv("XAUTHORITY")
+       if fn == "" {
+               home := os.Getenv("HOME")
+               if home == "" {
+                       err = os.NewError("Xauthority not found: $XAUTHORITY, $HOME not set")
+                       return
+               }
+               fn = home + "/.Xauthority"
        }
-       r, err := os.Open(home+"/.Xauthority", os.O_RDONLY, 0444)
+       r, err := os.Open(fn, os.O_RDONLY, 0444)
        if err != nil {
                return
        }