cmd/go: prefer <meta> tags on launchpad.net to the hard-coded logic

Fixes #11436.

Change-Id: I5c4455e9b13b478838f23ac31e6343672dfc60af
Reviewed-on: https://go-review.googlesource.com/12143
Reviewed-by: Michael Hudson-Doyle <michael.hudson@canonical.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/cmd/go/vcs.go b/src/cmd/go/vcs.go
index 8871f77371c0217b6090057567cee1bc7556ec21..2ee1057a5839cf192571532291c47b1ee54f4296 100644 (file)
--- a/src/cmd/go/vcs.go
+++ b/src/cmd/go/vcs.go
@@ -557,7 +557,7 @@ const (
 // repoRootForImportPath analyzes importPath to determine the
 // version control system, and code repository to use.
 func repoRootForImportPath(importPath string, security securityMode) (*repoRoot, error) {
-       rr, err := repoRootForImportPathStatic(importPath, "", security)
+       rr, err := repoRootFromVCSPaths(importPath, "", security, vcsPaths)
        if err == errUnknownSite {
                // If there are wildcards, look up the thing before the wildcard,
                // hoping it applies to the wildcarded parts too.
@@ -579,6 +579,13 @@ func repoRootForImportPath(importPath string, security securityMode) (*repoRoot,
                        err = fmt.Errorf("unrecognized import path %q", importPath)
                }
        }
+       if err != nil {
+               rr1, err1 := repoRootFromVCSPaths(importPath, "", security, vcsPathsAfterDynamic)
+               if err1 == nil {
+                       rr = rr1
+                       err = nil
+               }
+       }
 
        if err == nil && strings.Contains(importPath, "...") && strings.Contains(rr.root, "...") {
                // Do not allow wildcards in the repo root.
@@ -590,13 +597,10 @@ func repoRootForImportPath(importPath string, security securityMode) (*repoRoot,
 
 var errUnknownSite = errors.New("dynamic lookup required to find mapping")
 
-// repoRootForImportPathStatic attempts to map importPath to a
-// repoRoot using the commonly-used VCS hosting sites in vcsPaths
-// (github.com/user/dir), or from a fully-qualified importPath already
-// containing its VCS type (foo.com/repo.git/dir)
-//
+// repoRootFromVCSPaths attempts to map importPath to a repoRoot
+// using the mappings defined in vcsPaths.
 // If scheme is non-empty, that scheme is forced.
-func repoRootForImportPathStatic(importPath, scheme string, security securityMode) (*repoRoot, error) {
+func repoRootFromVCSPaths(importPath, scheme string, security securityMode, vcsPaths []*vcsPath) (*repoRoot, error) {
        // A common error is to use https://packagepath because that's what
        // hg and git require. Diagnose this helpfully.
        if loc := httpPrefixRE.FindStringIndex(importPath); loc != nil {
@@ -831,7 +835,10 @@ func expand(match map[string]string, s string) string {
        return s
 }
 
-// vcsPaths lists the known vcs paths.
+// vcsPaths defines the meaning of import paths referring to
+// commonly-used VCS hosting sites (github.com/user/dir)
+// and import paths referring to a fully-qualified importPath
+// containing a VCS type (foo.com/repo.git/dir)
 var vcsPaths = []*vcsPath{
        // Google Code - new syntax
        {
@@ -864,15 +871,6 @@ var vcsPaths = []*vcsPath{
                check:  bitbucketVCS,
        },
 
-       // Launchpad
-       {
-               prefix: "launchpad.net/",
-               re:     `^(?P<root>launchpad\.net/((?P<project>[A-Za-z0-9_.\-]+)(?P<series>/[A-Za-z0-9_.\-]+)?|~[A-Za-z0-9_.\-]+/(\+junk|[A-Za-z0-9_.\-]+)/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`,
-               vcs:    "bzr",
-               repo:   "https://{root}",
-               check:  launchpadVCS,
-       },
-
        // IBM DevOps Services (JazzHub)
        {
                prefix: "hub.jazz.net/git",
@@ -891,12 +889,28 @@ var vcsPaths = []*vcsPath{
        },
 
        // General syntax for any server.
+       // Must be last.
        {
                re:   `^(?P<root>(?P<repo>([a-z0-9.\-]+\.)+[a-z0-9.\-]+(:[0-9]+)?/[A-Za-z0-9_.\-/]*?)\.(?P<vcs>bzr|git|hg|svn))(/[A-Za-z0-9_.\-]+)*$`,
                ping: true,
        },
 }
 
+// vcsPathsAfterDynamic gives additional vcsPaths entries
+// to try after the dynamic HTML check.
+// This gives those sites a chance to introduce <meta> tags
+// as part of a graceful transition away from the hard-coded logic.
+var vcsPathsAfterDynamic = []*vcsPath{
+       // Launchpad. See golang.org/issue/11436.
+       {
+               prefix: "launchpad.net/",
+               re:     `^(?P<root>launchpad\.net/((?P<project>[A-Za-z0-9_.\-]+)(?P<series>/[A-Za-z0-9_.\-]+)?|~[A-Za-z0-9_.\-]+/(\+junk|[A-Za-z0-9_.\-]+)/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`,
+               vcs:    "bzr",
+               repo:   "https://{root}",
+               check:  launchpadVCS,
+       },
+}
+
 func init() {
        // fill in cached regexps.
        // Doing this eagerly discovers invalid regexp syntax
@@ -904,6 +918,9 @@ func init() {
        for _, srv := range vcsPaths {
                srv.regexp = regexp.MustCompile(srv.re)
        }
+       for _, srv := range vcsPathsAfterDynamic {
+               srv.regexp = regexp.MustCompile(srv.re)
+       }
 }
 
 // noVCSSuffix checks that the repository name does not