cmd/go: do not force use of git master branch (again)

This time with a test.
Also adjust another test to skip when hg is not present,
and delete no longer needed fixDetachedHead code.

Fixes #9032 (again).

Change-Id: I481717409e1d44b524f83c70a8dc377699d1a2a5
Reviewed-on: https://go-review.googlesource.com/18334
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/cmd/go/go_test.go b/src/cmd/go/go_test.go
index 6dc08cf9ce05cfa1ae770644122e664588b6db1d..cc36b43de3beaf99528b98078fb9d1347f93cf7e 100644 (file)
--- a/src/cmd/go/go_test.go
+++ b/src/cmd/go/go_test.go
@@ -1063,7 +1063,6 @@ func TestImportCommentConflict(t *testing.T) {
 // cmd/go: custom import path checking should not apply to github.com/xxx/yyy.
 func TestIssue10952(t *testing.T) {
        testenv.MustHaveExternalNetwork(t)
-
        if _, err := exec.LookPath("git"); err != nil {
                t.Skip("skipping because git binary not found")
        }
@@ -1081,6 +1080,34 @@ func TestIssue10952(t *testing.T) {
        tg.run("get", "-d", "-u", importPath)
 }
 
+func TestGetGitDefaultBranch(t *testing.T) {
+       testenv.MustHaveExternalNetwork(t)
+       if _, err := exec.LookPath("git"); err != nil {
+               t.Skip("skipping because git binary not found")
+       }
+
+       tg := testgo(t)
+       defer tg.cleanup()
+       tg.parallel()
+       tg.tempDir("src")
+       tg.setenv("GOPATH", tg.path("."))
+
+       // This repo has two branches, master and another-branch.
+       // The another-branch is the default that you get from 'git clone'.
+       // The go get command variants should not override this.
+       const importPath = "github.com/rsc/go-get-default-branch"
+
+       tg.run("get", "-d", importPath)
+       repoDir := tg.path("src/" + importPath)
+       defer tg.resetReadOnlyFlagAll(repoDir)
+       tg.runGit(repoDir, "branch", "--contains", "HEAD")
+       tg.grepStdout(`\* another-branch`, "not on correct default branch")
+
+       tg.run("get", "-d", "-u", importPath)
+       tg.runGit(repoDir, "branch", "--contains", "HEAD")
+       tg.grepStdout(`\* another-branch`, "not on correct default branch")
+}
+
 func TestDisallowedCSourceFiles(t *testing.T) {
        tg := testgo(t)
        defer tg.cleanup()
@@ -2219,6 +2246,9 @@ func TestGoGetInsecureCustomDomain(t *testing.T) {
 
 func TestIssue10193(t *testing.T) {
        testenv.MustHaveExternalNetwork(t)
+       if _, err := exec.LookPath("hg"); err != nil {
+               t.Skip("skipping because hg binary not found")
+       }
 
        tg := testgo(t)
        defer tg.cleanup()

diff --git a/src/cmd/go/vcs.go b/src/cmd/go/vcs.go
index 59e72c6de2cf37cfda28b8a50456bcabbc99471b..074dd8b2b1259bb7bb7105af9b474b5009bd76c0 100644 (file)
--- a/src/cmd/go/vcs.go
+++ b/src/cmd/go/vcs.go
@@ -137,8 +137,9 @@ var vcsGit = &vcsCmd{
        // both createCmd and downloadCmd update the working dir.
        // No need to do more here. We used to 'checkout master'
        // but that doesn't work if the default branch is not named master.
+       // DO NOT add 'checkout master' here.
        // See golang.org/issue/9032.
-       tagSyncDefault: []string{"checkout master", "submodule update --init --recursive"},
+       tagSyncDefault: []string{"submodule update --init --recursive"},
 
        scheme:     []string{"git", "https", "http", "git+ssh", "ssh"},
        pingCmd:    "ls-remote {scheme}://{repo}",
@@ -385,9 +386,6 @@ func (v *vcsCmd) create(dir, repo string) error {
 
 // download downloads any new changes for the repo in dir.
 func (v *vcsCmd) download(dir string) error {
-       if err := v.fixDetachedHead(dir); err != nil {
-               return err
-       }
        for _, cmd := range v.downloadCmd {
                if !go15VendorExperiment && strings.Contains(cmd, "submodule") {
                        continue
@@ -399,30 +397,6 @@ func (v *vcsCmd) download(dir string) error {
        return nil
 }
 
-// fixDetachedHead switches a Git repository in dir from a detached head to the master branch.
-// Go versions before 1.2 downloaded Git repositories in an unfortunate way
-// that resulted in the working tree state being on a detached head.
-// That meant the repository was not usable for normal Git operations.
-// Go 1.2 fixed that, but we can't pull into a detached head, so if this is
-// a Git repository we check for being on a detached head and switch to the
-// real branch, almost always called "master".
-// TODO(dsymonds): Consider removing this for Go 1.3.
-func (v *vcsCmd) fixDetachedHead(dir string) error {
-       if v != vcsGit {
-               return nil
-       }
-
-       // "git symbolic-ref HEAD" succeeds iff we are not on a detached head.
-       if err := v.runVerboseOnly(dir, "symbolic-ref HEAD"); err == nil {
-               // not on a detached head
-               return nil
-       }
-       if buildV {
-               log.Printf("%s on detached head; repairing", dir)
-       }
-       return v.run(dir, "checkout master")
-}
-
 // tags returns the list of available tags for the repo in dir.
 func (v *vcsCmd) tags(dir string) ([]string, error) {
        var tags []string