cmd/go/internal/get: simplify scheme lookup

Fixes #26123

Change-Id: If0dad65a3885d2146624f2aac42099e9eca9670e
Reviewed-on: https://go-review.googlesource.com/c/go/+/200758
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Jay Conrod <jayconrod@google.com>

diff --git a/src/cmd/go/internal/get/vcs.go b/src/cmd/go/internal/get/vcs.go
index 3ccfbb8837594e22cf86c7a8428184dbd984c9eb..d73d1146f0f3ed961400c4ca7325bf9f2372e998 100644 (file)
--- a/src/cmd/go/internal/get/vcs.go
+++ b/src/cmd/go/internal/get/vcs.go
@@ -531,12 +531,12 @@ func (v *vcsCmd) tagSync(dir, tag string) error {
 // A vcsPath describes how to convert an import path into a
 // version control system and repository name.
 type vcsPath struct {
-       prefix string                              // prefix this description applies to
-       regexp *lazyregexp.Regexp                  // compiled pattern for import path
-       repo   string                              // repository to use (expand with match of re)
-       vcs    string                              // version control system to use (expand with match of re)
-       check  func(match map[string]string) error // additional checks
-       ping   bool                                // ping for scheme to use to download repo
+       prefix         string                              // prefix this description applies to
+       regexp         *lazyregexp.Regexp                  // compiled pattern for import path
+       repo           string                              // repository to use (expand with match of re)
+       vcs            string                              // version control system to use (expand with match of re)
+       check          func(match map[string]string) error // additional checks
+       schemelessRepo bool                                // if true, the repo pattern lacks a scheme
 }
 
 // vcsFromDir inspects dir and its parents to determine the
@@ -657,7 +657,7 @@ const (
 // RepoRootForImportPath analyzes importPath to determine the
 // version control system, and code repository to use.
 func RepoRootForImportPath(importPath string, mod ModuleMode, security web.SecurityMode) (*RepoRoot, error) {
-       rr, err := repoRootFromVCSPaths(importPath, "", security, vcsPaths)
+       rr, err := repoRootFromVCSPaths(importPath, security, vcsPaths)
        if err == errUnknownSite {
                rr, err = repoRootForImportDynamic(importPath, mod, security)
                if err != nil {
@@ -665,7 +665,7 @@ func RepoRootForImportPath(importPath string, mod ModuleMode, security web.Secur
                }
        }
        if err != nil {
-               rr1, err1 := repoRootFromVCSPaths(importPath, "", security, vcsPathsAfterDynamic)
+               rr1, err1 := repoRootFromVCSPaths(importPath, security, vcsPathsAfterDynamic)
                if err1 == nil {
                        rr = rr1
                        err = nil
@@ -685,8 +685,7 @@ var errUnknownSite = errors.New("dynamic lookup required to find mapping")
 
 // repoRootFromVCSPaths attempts to map importPath to a repoRoot
 // using the mappings defined in vcsPaths.
-// If scheme is non-empty, that scheme is forced.
-func repoRootFromVCSPaths(importPath, scheme string, security web.SecurityMode, vcsPaths []*vcsPath) (*RepoRoot, error) {
+func repoRootFromVCSPaths(importPath string, security web.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 prefix := httpPrefix(importPath); prefix != "" {
@@ -731,26 +730,28 @@ func repoRootFromVCSPaths(importPath, scheme string, security web.SecurityMode,
                if vcs == nil {
                        return nil, fmt.Errorf("unknown version control system %q", match["vcs"])
                }
-               if srv.ping {
-                       if scheme != "" {
-                               match["repo"] = scheme + "://" + match["repo"]
-                       } else {
-                               for _, scheme := range vcs.scheme {
-                                       if security == web.SecureOnly && !vcs.isSecureScheme(scheme) {
+               var repoURL string
+               if !srv.schemelessRepo {
+                       repoURL = match["repo"]
+               } else {
+                       scheme := vcs.scheme[0] // default to first scheme
+                       repo := match["repo"]
+                       if vcs.pingCmd != "" {
+                               // If we know how to test schemes, scan to find one.
+                               for _, s := range vcs.scheme {
+                                       if security == web.SecureOnly && !vcs.isSecureScheme(s) {
                                                continue
                                        }
-                                       if vcs.pingCmd != "" && vcs.ping(scheme, match["repo"]) == nil {
-                                               match["repo"] = scheme + "://" + match["repo"]
-                                               goto Found
+                                       if vcs.ping(s, repo) == nil {
+                                               scheme = s
+                                               break
                                        }
                                }
-                               // No scheme found. Fall back to the first one.
-                               match["repo"] = vcs.scheme[0] + "://" + match["repo"]
-                       Found:
                        }
+                       repoURL = scheme + "://" + repo
                }
                rr := &RepoRoot{
-                       Repo: match["repo"],
+                       Repo: repoURL,
                        Root: match["root"],
                        VCS:  vcs.cmd,
                        vcs:  vcs,
@@ -1075,8 +1076,8 @@ var vcsPaths = []*vcsPath{
        // General syntax for any server.
        // Must be last.
        {
-               regexp: lazyregexp.New(`(?P<root>(?P<repo>([a-z0-9.\-]+\.)+[a-z0-9.\-]+(:[0-9]+)?(/~?[A-Za-z0-9_.\-]+)+?)\.(?P<vcs>bzr|fossil|git|hg|svn))(/~?[A-Za-z0-9_.\-]+)*$`),
-               ping:   true,
+               regexp:         lazyregexp.New(`(?P<root>(?P<repo>([a-z0-9.\-]+\.)+[a-z0-9.\-]+(:[0-9]+)?(/~?[A-Za-z0-9_.\-]+)+?)\.(?P<vcs>bzr|fossil|git|hg|svn))(/~?[A-Za-z0-9_.\-]+)*$`),
+               schemelessRepo: true,
        },
 }