cmd/go: fix go get x/... matching internal directories

Fixes #11960.

Change-Id: I9361a9f17f4eaf8e4f54b4ba380fd50a4b9cf003
Reviewed-on: https://go-review.googlesource.com/13023Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/cmd/go/get.go

@@ -208,9 +208,6 @@ func download(arg string, parent *Package, stk *importStack, mode int) {
 	wildcardOkay := len(*stk) == 0
 	isWildcard := false
 
-	// Note: Do not stk.push(arg) and defer stk.pop() here.
-	// The push/pop below are using updated values of arg in some cases.
-
 	// Download if the package is missing, or update if we're using -u.
 	if p.Dir == "" || *getU {
 		// The actual download.
@@ -258,9 +255,10 @@ func download(arg string, parent *Package, stk *importStack, mode int) {
 
 		pkgs = pkgs[:0]
 		for _, arg := range args {
-			stk.push(arg)
+			// Note: load calls loadPackage or loadImport,
+			// which push arg onto stk already.
+			// Do not push here too, or else stk will say arg imports arg.
 			p := load(arg, mode)
-			stk.pop()
 			if p.Error != nil {
 				errorf("%s", p.Error)
 				continue

src/cmd/go/go_test.go

@@ -1961,7 +1961,7 @@ func TestGoGenerateRunFlag(t *testing.T) {
 	tg.grepStdoutNot("no", "go generate -run yes ./testdata/generate/test4.go selected no")
 }
 
-func TestGoGetWorksWithVanityWildcards(t *testing.T) {
+func TestGoGetCustomDomainWildcard(t *testing.T) {
 	testenv.MustHaveExternalNetwork(t)
 
 	tg := testgo(t)
@@ -1972,6 +1972,17 @@ func TestGoGetWorksWithVanityWildcards(t *testing.T) {
 	tg.wantExecutable(tg.path("bin/pdfpasswd"+exeSuffix), "did not build rsc/io/pdf/pdfpasswd")
 }
 
+func TestGoGetInternalWildcard(t *testing.T) {
+	testenv.MustHaveExternalNetwork(t)
+
+	tg := testgo(t)
+	defer tg.cleanup()
+	tg.makeTempdir()
+	tg.setenv("GOPATH", tg.path("."))
+	// used to fail with errors about internal packages
+	tg.run("get", "github.com/rsc/go-get-issue-11960/...")
+}
+
 func TestGoVetWithExternalTests(t *testing.T) {
 	testenv.MustHaveExternalNetwork(t)