2 files changed, 38 insertions, 13 deletions

diff --git a/libgo/go/net/http/cgi/host.go b/libgo/go/net/http/cgi/host.go
index 4efbe7a..9b4d875 100644
--- a/libgo/go/net/http/cgi/host.go
+++ b/libgo/go/net/http/cgi/host.go
@@ -77,15 +77,15 @@ type Handler struct {
 //      Env: []string{"SCRIPT_FILENAME=foo.php"},
 //    }
 func removeLeadingDuplicates(env []string) (ret []string) {
-	n := len(env)
-	for i := 0; i < n; i++ {
-		e := env[i]
-		s := strings.SplitN(e, "=", 2)[0]
+	for i, e := range env {
 		found := false
-		for j := i + 1; j < n; j++ {
-			if s == strings.SplitN(env[j], "=", 2)[0] {
-				found = true
-				break
+		if eq := strings.IndexByte(e, '='); eq != -1 {
+			keq := e[:eq+1] // "key="
+			for _, e2 := range env[i+1:] {
+				if strings.HasPrefix(e2, keq) {
+					found = true
+					break
+				}
 			}
 		}
 		if !found {
@@ -159,10 +159,6 @@ func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		env = append(env, "CONTENT_TYPE="+ctype)
 	}
 
-	if h.Env != nil {
-		env = append(env, h.Env...)
-	}
-
 	envPath := os.Getenv("PATH")
 	if envPath == "" {
 		envPath = "/bin:/usr/bin:/usr/ucb:/usr/bsd:/usr/local/bin"
@@ -181,6 +177,10 @@ func (h *Handler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 		}
 	}
 
+	if h.Env != nil {
+		env = append(env, h.Env...)
+	}
+
 	env = removeLeadingDuplicates(env)
 
 	var cwd, path string
diff --git a/libgo/go/net/http/cgi/host_test.go b/libgo/go/net/http/cgi/host_test.go
index f341110..fb7d66a 100644
--- a/libgo/go/net/http/cgi/host_test.go
+++ b/libgo/go/net/http/cgi/host_test.go
@@ -16,6 +16,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"reflect"
 	"runtime"
 	"strconv"
 	"strings"
@@ -488,12 +489,36 @@ func TestEnvOverride(t *testing.T) {
 		Args: []string{cgifile},
 		Env: []string{
 			"SCRIPT_FILENAME=" + cgifile,
-			"REQUEST_URI=/foo/bar"},
+			"REQUEST_URI=/foo/bar",
+			"PATH=/wibble"},
 	}
 	expectedMap := map[string]string{
 		"cwd": cwd,
 		"env-SCRIPT_FILENAME": cgifile,
 		"env-REQUEST_URI":     "/foo/bar",
+		"env-PATH":            "/wibble",
 	}
 	runCgiTest(t, h, "GET /test.cgi HTTP/1.0\nHost: example.com\n\n", expectedMap)
 }
+
+func TestRemoveLeadingDuplicates(t *testing.T) {
+	tests := []struct {
+		env  []string
+		want []string
+	}{
+		{
+			env:  []string{"a=b", "b=c", "a=b2"},
+			want: []string{"b=c", "a=b2"},
+		},
+		{
+			env:  []string{"a=b", "b=c", "d", "e=f"},
+			want: []string{"a=b", "b=c", "d", "e=f"},
+		},
+	}
+	for _, tt := range tests {
+		got := removeLeadingDuplicates(tt.env)
+		if !reflect.DeepEqual(got, tt.want) {
+			t.Errorf("removeLeadingDuplicates(%q) = %q; want %q", tt.env, got, tt.want)
+		}
+	}
+}