code review 5708054: cmd/go: fixes

src/cmd/go/vcs.go

 // Copyright 2012 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package main
 
 import (
         "bytes"
         "encoding/json"
         "fmt"
         "os"
         "os/exec"
+        "path/filepath"
         "regexp"
         "strings"
 )
 
 // A vcsCmd describes how to use a version control system
 // like Mercurial, Git, or Subversion.
 type vcsCmd struct {
         name string
         cmd  string // name of binary to invoke command
 
@@ skipping 239 matching lines @@
         prefix string                              // prefix this description applies to
         re     string                              // 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
 
         regexp *regexp.Regexp // cached compiled form of re
 }
 
+// vcsForDir inspects dir and its parents to determine the
+// version control system and code repository to use.
+// On return, root is the import path
+// corresponding to the root of the repository
+// (thus root is a prefix of importPath).
+func vcsForDir(p *Package) (vcs *vcsCmd, root string, err error) {
+        // Clean and double-check that dir is in (a subdirectory of) srcRoot.
+        dir := filepath.Clean(p.Dir)
+        srcRoot := filepath.Clean(p.build.SrcRoot)
+        if len(dir) <= len(srcRoot) || dir[len(srcRoot)] != filepath.Separator {
+                return nil, "", fmt.Errorf("directory %q is outside source root %q", dir, srcRoot)
+        }
+
+        for len(dir) > len(srcRoot) {
+                for _, vcs := range vcsList {
+                        if fi, err := os.Stat(filepath.Join(dir, "."+vcs.cmd)); err == nil && fi.IsDir() {
+                                return vcs, dir[len(srcRoot)+1:], nil
+                        }
+                }
+
+                // Move to parent.
+                ndir := filepath.Dir(dir)
+                if len(ndir) >= len(dir) {
+                        // Shouldn't happen, but just in case, stop.
+                        break
+                }
+                dir = ndir
+        }
+
+        return nil, "", fmt.Errorf("directory %q is not using a known version control system", dir)
+}
+
 // vcsForImportPath analyzes importPath to determine the
 // version control system, and code repository to use.
 // On return, repo is the repository URL and root is the
 // import path corresponding to the root of the repository
 // (thus root is a prefix of importPath).
 func vcsForImportPath(importPath string) (vcs *vcsCmd, repo, root string, err error) {
         for _, srv := range vcsPaths {
                 if !strings.HasPrefix(importPath, srv.prefix) {
                         continue
                 }
@@ skipping 199 matching lines @@
         if match["project"] == "" || match["series"] == "" {
                 return nil
         }
         _, err := httpGET(expand(match, "https://code.launchpad.net/{project}{series}/.bzr/branch-format"))
         if err != nil {
                 match["root"] = expand(match, "launchpad.net/{project}")
                 match["repo"] = expand(match, "https://{root}")
         }
         return nil
 }