Improve finding git remote to fetch from in new `checkout`

The remote needs to match the base project from the pull request.

commands/checkout.go

@@ -78,31 +78,22 @@ func transformCheckoutArgs(args *Args) error {
 		args.RemoveParam(idx)
 	}
 
-	branch := pullRequest.Head.Ref
-	headRepo := pullRequest.Head.Repo
-	if headRepo == nil {
-		return fmt.Errorf("Error: that fork is not available anymore")
+	repo, err := github.LocalRepo()
+	if err != nil {
+		return err
+	}
+
+	remote, err := repo.RemoteForRepo(pullRequest.Base.Repo)
+	if err != nil {
+		return err
 	}
-	user := headRepo.Owner.Login
 
 	if newBranchName == "" {
-		newBranchName = fmt.Sprintf("%s-%s", user, branch)
-	}
-
-	repo, err := github.LocalRepo()
-	utils.Check(err)
-
-	var remoteRepo string
-
-	_, err = repo.RemoteByName(user)
-	if err == nil {
-		remoteRepo = user
-	} else {
-		remoteRepo = url.GitURL("", "", false)
+		newBranchName = fmt.Sprintf("%s-%s", pullRequest.Head.Repo.Owner.Login, pullRequest.Head.Ref)
 	}
 
 	branchMapping := fmt.Sprintf("pull/%s/head:%s", id, newBranchName)
-	args.Before("git", "fetch", remoteRepo, branchMapping)
+	args.Before("git", "fetch", remote.Name, branchMapping)
 	replaceCheckoutParam(args, checkoutURL, newBranchName)
 
 	return nil

features/checkout.feature

@@ -19,30 +19,38 @@ Feature: hub checkout <PULLREQ-URL>
             :name => "jekyll",
             :private => false
           }
-        }
-      }
-      """
-    When I run `hub checkout -f https://github.com/mojombo/jekyll/pull/77 -q`
-    Then "git fetch git://github.com/mojombo/jekyll.git pull/77/head:mislav-fixes" should be run
-    And "git checkout -f mislav-fixes -q" should be run
-
-  Scenario: Pull request from a renamed fork
-    Given the GitHub API server:
-      """
-      get('/repos/mojombo/jekyll/pulls/77') {
-        json :head => {
-          :ref => "fixes",
+        }, :base => {
           :repo => {
-            :owner => { :login => "mislav" },
-            :name => "jekyll-blog",
-            :private => false
+            :name => 'jekyll',
+            :html_url => 'https://github.com/mojombo/jekyll',
+            :owner => { :login => "mojombo" },
           }
         }
       }
       """
-    When I run `hub checkout https://github.com/mojombo/jekyll/pull/77`
-    Then "git fetch git://github.com/mojombo/jekyll.git pull/77/head:mislav-fixes" should be run
-    And "git checkout mislav-fixes" should be run
+    When I run `hub checkout -f https://github.com/mojombo/jekyll/pull/77 -q`
+    Then "git fetch origin pull/77/head:mislav-fixes" should be run
+    And "git checkout -f mislav-fixes -q" should be run
+
+  Scenario: No matching remotes for pull request base
+    Given the GitHub API server:
+      """
+      get('/repos/mislav/jekyll/pulls/77') {
+        json :base => {
+          :repo => {
+            :name => 'jekyll',
+            :html_url => 'https://github.com/mislav/jekyll',
+            :owner => { :login => "mislav" },
+          }
+        }
+      }
+      """
+    When I run `hub checkout -f https://github.com/mislav/jekyll/pull/77 -q`
+    Then the exit status should be 1
+    And the stderr should contain exactly:
+      """
+      could not find git remote for mislav/jekyll\n
+      """
 
   Scenario: Custom name for new branch
     Given the GitHub API server:
@@ -51,50 +59,18 @@ Feature: hub checkout <PULLREQ-URL>
         json :head => {
           :ref => "fixes",
           :repo => {
-            :owner => { :login => "mislav" },
             :name => "jekyll",
-            :private => false
+            :owner => { :login => "mislav" },
+          }
+        }, :base => {
+          :repo => {
+            :name => 'jekyll',
+            :html_url => 'https://github.com/mojombo/jekyll',
+            :owner => { :login => "mojombo" },
           }
         }
       }
       """
     When I run `hub checkout https://github.com/mojombo/jekyll/pull/77 fixes-from-mislav`
-    Then "git fetch git://github.com/mojombo/jekyll.git pull/77/head:fixes-from-mislav" should be run
+    Then "git fetch origin pull/77/head:fixes-from-mislav" should be run
     And "git checkout fixes-from-mislav" should be run
-
-  Scenario: Private pull request
-    Given the GitHub API server:
-      """
-      get('/repos/mojombo/jekyll/pulls/77') {
-        json :head => {
-          :ref => "fixes",
-          :repo => {
-            :owner => { :login => "mislav" },
-            :name => "jekyll",
-            :private => true
-          }
-        }
-      }
-      """
-    When I run `hub checkout -f https://github.com/mojombo/jekyll/pull/77 -q`
-    Then "git fetch git://github.com/mojombo/jekyll.git pull/77/head:mislav-fixes" should be run
-    And "git checkout -f mislav-fixes -q" should be run
-
-  Scenario: Remote for user already exists
-    Given the GitHub API server:
-      """
-      get('/repos/mojombo/jekyll/pulls/77') {
-        json :head => {
-          :ref => "fixes",
-          :repo => {
-            :owner => { :login => "mislav" },
-            :name => "jekyll",
-            :private => false
-          }
-        }
-      }
-      """
-    And the "mislav" remote has url "git://github.com/mislav/jekyll.git"
-    When I run `hub checkout https://github.com/mojombo/jekyll/pull/77`
-    Then "git fetch mislav pull/77/head:mislav-fixes" should be run
-    And "git checkout mislav-fixes" should be run

github/localrepo.go

@@ -2,6 +2,7 @@ package github
 
 import (
 	"fmt"
+	"net/url"
 	"strings"
 
 	"github.com/github/hub/git"
@@ -148,6 +149,27 @@ func (r *GitHubRepo) RemoteBranchAndProject(owner string, preferUpstream bool) (
 	return
 }
 
+func (r *GitHubRepo) RemoteForRepo(repo *Repository) (*Remote, error) {
+	r.loadRemotes()
+
+	repoUrl, err := url.Parse(repo.HtmlUrl)
+	if err != nil {
+		return nil, err
+	}
+
+	project := NewProject(repo.Owner.Login, repo.Name, repoUrl.Host)
+
+	for _, remote := range r.remotes {
+		if rp, err := remote.Project(); err == nil {
+			if rp.SameAs(project) {
+				return &remote, nil
+			}
+		}
+	}
+
+	return nil, fmt.Errorf("could not find git remote for %s/%s", repo.Owner.Login, repo.Name)
+}
+
 func (r *GitHubRepo) OriginRemote() (remote *Remote, err error) {
 	return r.RemoteByName("origin")
 }