goinstall/download.go: Add checkout concept and helper functions to clean and fix...

R=rsc, niemeyer, adg
CC=golang-dev
https://golang.org/cl/3536041

diff --git a/src/cmd/goinstall/download.go b/src/cmd/goinstall/download.go
index 76aabb812f12bda06cdfc123b5f34eb861d9c35a..61cabca17e57d4f4262874821c392f17d626c5a9 100644 (file)
--- a/src/cmd/goinstall/download.go
+++ b/src/cmd/goinstall/download.go
@@ -88,6 +88,7 @@ func download(pkg string) (string, os.Error) {
 type vcs struct {
        cmd               string
        metadir           string
+       checkout          string
        clone             string
        update            string
        updateReleaseFlag string
@@ -101,6 +102,7 @@ type vcs struct {
 var hg = vcs{
        cmd:               "hg",
        metadir:           ".hg",
+       checkout:          "checkout",
        clone:             "clone",
        update:            "update",
        updateReleaseFlag: "release",
@@ -113,18 +115,20 @@ var hg = vcs{
 var git = vcs{
        cmd:               "git",
        metadir:           ".git",
+       checkout:          "checkout",
        clone:             "clone",
        update:            "pull",
        updateReleaseFlag: "release",
        pull:              "fetch",
-       log:               "log",
-       logLimitFlag:      "-n1",
+       log:               "show-ref",
+       logLimitFlag:      "",
        logReleaseFlag:    "release",
 }
 
 var svn = vcs{
        cmd:               "svn",
        metadir:           ".svn",
+       checkout:          "checkout",
        clone:             "checkout",
        update:            "update",
        updateReleaseFlag: "release",
@@ -136,6 +140,7 @@ var svn = vcs{
 var bzr = vcs{
        cmd:               "bzr",
        metadir:           ".bzr",
+       checkout:          "checkout",
        clone:             "branch",
        update:            "update",
        updateReleaseFlag: "-rrelease",
@@ -146,6 +151,22 @@ var bzr = vcs{
        logReleaseFlag:    "-rrelease",
 }
 
+// Try to detect if a "release" tag exists.  If it does, update
+// to the tagged version, otherwise just update the current branch.
+// NOTE(_nil): svn will always fail because it is trying to get
+// the revision history of a file named "release" instead of
+// looking for a commit with a release tag
+func (v *vcs) updateRepo(dst string) os.Error {
+       if err := quietRun(dst, nil, v.cmd, v.log, v.logLimitFlag, v.logReleaseFlag); err == nil {
+               if err := run(dst, nil, v.cmd, v.checkout, v.updateReleaseFlag); err != nil {
+                       return err
+               }
+       } else if err := run(dst, nil, v.cmd, v.update); err != nil {
+               return err
+       }
+       return nil
+}
+
 // vcsCheckout checks out repo into dst using vcs.
 // It tries to check out (or update, if the dst already
 // exists and -u was specified on the command line)
@@ -164,8 +185,9 @@ func vcsCheckout(vcs *vcs, dst, repo, dashpath string) os.Error {
                if err := run("/", nil, vcs.cmd, vcs.clone, repo, dst); err != nil {
                        return err
                }
-               quietRun(dst, nil, vcs.cmd, vcs.update, vcs.updateReleaseFlag)
-
+               if err := vcs.updateRepo(dst); err != nil {
+                       return err
+               }
                // success on first installation - report
                maybeReportToDashboard(dashpath)
        } else if *update {
@@ -181,19 +203,8 @@ func vcsCheckout(vcs *vcs, dst, repo, dashpath string) os.Error {
                        }
                }
 
-               // Try to detect if a "release" tag exists.  If it does, update
-               // to the tagged version.  If no tag is found, then update to the
-               // tip afterwards.
-               // NOTE(gustavo@niemeyer.net): What is the expected behavior with
-               // svn here? "svn log -l1 release" doesn't make sense in this
-               // context and will probably fail.
-               if err := quietRun(dst, nil, vcs.cmd, vcs.log, vcs.logLimitFlag, vcs.logReleaseFlag); err == nil {
-                       if err := run(dst, nil, vcs.cmd, vcs.update, vcs.updateReleaseFlag); err != nil {
-                               // The VCS supports tagging, has the "release" tag, but
-                               // something else went wrong.  Report.
-                               return err
-                       }
-               } else if err := run(dst, nil, vcs.cmd, vcs.update); err != nil {
+               // Update to release or latest revision
+               if err := vcs.updateRepo(dst); err != nil {
                        return err
                }
        }