cmd/go: set GOPATH in list's Context

Fixes #14547.

Change-Id: Ic175ee8f7e65b9b99f1f47fbf267a2aba7c8fec7
Reviewed-on: https://go-review.googlesource.com/20010
Run-TryBot: Caleb Spare <cespare@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>

src/cmd/go/context.go

@@ -26,6 +26,7 @@ func newContext(c *build.Context) *Context {
 		GOARCH:        c.GOARCH,
 		GOOS:          c.GOOS,
 		GOROOT:        c.GOROOT,
+		GOPATH:        c.GOPATH,
 		CgoEnabled:    c.CgoEnabled,
 		UseAllFiles:   c.UseAllFiles,
 		Compiler:      c.Compiler,

src/cmd/go/go_test.go

@@ -2105,10 +2105,33 @@ func main() { C.f() }`)
 	tg.grepStderr(`gccgo.*\-L alibpath \-lalib`, `no Go-inline "#cgo LDFLAGS:" ("-L alibpath -lalib") passed to gccgo linking stage`)
 }
 
-func TestListTemplateCanUseContextFunction(t *testing.T) {
-	tg := testgo(t)
-	defer tg.cleanup()
-	tg.run("list", "-f", "GOARCH: {{context.GOARCH}}")
+func TestListTemplateContextFunction(t *testing.T) {
+	tg := testgo(t)
+	defer tg.cleanup()
+	for _, tt := range []struct {
+		v    string
+		want string
+	}{
+		{"GOARCH", runtime.GOARCH},
+		{"GOOS", runtime.GOOS},
+		{"GOROOT", filepath.Clean(runtime.GOROOT())},
+		{"GOPATH", os.Getenv("GOPATH")},
+		{"CgoEnabled", ""},
+		{"UseAllFiles", ""},
+		{"Compiler", ""},
+		{"BuildTags", ""},
+		{"ReleaseTags", ""},
+		{"InstallSuffix", ""},
+	} {
+		tmpl := "{{context." + tt.v + "}}"
+		tg.run("list", "-f", tmpl)
+		if tt.want == "" {
+			continue
+		}
+		if got := strings.TrimSpace(tg.getStdout()); got != tt.want {
+			t.Errorf("go list -f %q: got %q; want %q", tmpl, got, tt.want)
+		}
+	}
 }
 
 // cmd/go: "go test" should fail if package does not build