From cd6009c276b94db65d354bb6b0037565bf7a47c3 Mon Sep 17 00:00:00 2001
From: Tobias Hunger <tobias.hunger@nokia.com>
Date: Tue, 5 Oct 2010 10:11:36 +0200
Subject: [PATCH] Git: Handle unusual HEADs

Handle detached HEADs as well as cloning from repositories that default
to another branch but master. This is relevant when clonig local
repositories.

Reviewed-by: Friedemann Kleint
---
 src/plugins/git/clonewizardpage.cpp | 29 +++++++++++++++++------------
 src/plugins/git/gitclient.cpp       | 21 ++++++++++++++++++---
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/src/plugins/git/clonewizardpage.cpp b/src/plugins/git/clonewizardpage.cpp
index ea0b762421a..0cbac9ca77b 100644
--- a/src/plugins/git/clonewizardpage.cpp
+++ b/src/plugins/git/clonewizardpage.cpp
@@ -45,6 +45,7 @@ struct CloneWizardPagePrivate {
     const QString gitPostFix;
     const QString protocolDelimiter;
     QCheckBox *deleteMasterCheckBox;
+    QString headBranch;
 };
 
 CloneWizardPagePrivate::CloneWizardPagePrivate() :
@@ -131,33 +132,32 @@ QSharedPointer<VCSBase::AbstractCheckoutJob> CloneWizardPage::createCheckoutJob(
 
      const QString binary = client->binary();
 
-     QStringList args;
-     args << QLatin1String("clone") << repository() << checkoutDir;
-
      VCSBase::ProcessCheckoutJob *job = new VCSBase::ProcessCheckoutJob;
      const QProcessEnvironment env = client->processEnvironment();
+
      // 1) Basic checkout step
+     QStringList args;
+     args << QLatin1String("clone") << repository() << checkoutDir;
      job->addStep(binary, args, workingDirectory, env);
      const QString checkoutBranch = branch();
 
      // 2) Checkout branch, change to checkoutDir
-     const QString masterBranch = QLatin1String("master");
-     if (!checkoutBranch.isEmpty() && checkoutBranch != masterBranch) {
+     if (!checkoutBranch.isEmpty() && checkoutBranch != d->headBranch) {
          // Create branch
          args.clear();
          args << QLatin1String("branch") << QLatin1String("--track")
-                 << checkoutBranch << (QLatin1String("origin/")  + checkoutBranch);
+              << checkoutBranch << (QLatin1String("origin/")  + checkoutBranch);
          job->addStep(binary, args, *checkoutPath, env);
          // Checkout branch
          args.clear();
          args << QLatin1String("checkout") << checkoutBranch;
          job->addStep(binary, args, *checkoutPath, env);
-         // Delete master if desired
-         if (deleteMasterBranch()) {
+         if (deleteMasterBranch() && d->headBranch != QLatin1String("<detached HEAD>")) {
+             // Make sure we only have the requested branch:
              args.clear();
-             args << QLatin1String("branch") << QLatin1String("-D") << masterBranch;
-             job->addStep(binary, args, *checkoutPath, env);
+             args << QLatin1String("branch") << QLatin1String("-D") << d->headBranch;
          }
+         job->addStep(binary, args, *checkoutPath, env);
      }
 
      return QSharedPointer<VCSBase::AbstractCheckoutJob>(job);
@@ -166,11 +166,16 @@ QSharedPointer<VCSBase::AbstractCheckoutJob> CloneWizardPage::createCheckoutJob(
 QStringList CloneWizardPage::branches(const QString &repository, int *current)
 {
     // Run git on remote repository if an URL was specified.
-    *current = 0;
+    *current = -1;
+    d->headBranch.clear();
+
     if (repository.isEmpty())
         return QStringList();
      const QStringList branches = Internal::GitPlugin::instance()->gitClient()->synchronousRepositoryBranches(repository);
-     *current = branches.indexOf(QLatin1String("master"));
+     if (!branches.isEmpty()) {
+         *current = 0; // default branch is always returned first!
+         d->headBranch = branches.at(0);
+     }
      return branches;
 }
 
diff --git a/src/plugins/git/gitclient.cpp b/src/plugins/git/gitclient.cpp
index 9837b7c35a7..3e72a4e52ce 100644
--- a/src/plugins/git/gitclient.cpp
+++ b/src/plugins/git/gitclient.cpp
@@ -1279,22 +1279,37 @@ GitClient::StatusResult GitClient::gitStatus(const QString &workingDirectory,
 }
 
 // Quietly retrieve branch list of remote repository URL
+//
+// The branch HEAD is pointing to is always returned first.
 QStringList GitClient::synchronousRepositoryBranches(const QString &repositoryURL)
 {
     QStringList arguments(QLatin1String("ls-remote"));
-    arguments << QLatin1String("--heads") << repositoryURL;
+    arguments << repositoryURL << QLatin1String("HEAD") << QLatin1String("refs/heads/*");
     const unsigned flags =
             VCSBase::VCSBasePlugin::SshPasswordPrompt|
             VCSBase::VCSBasePlugin::SuppressStdErrInLogWindow|
             VCSBase::VCSBasePlugin::SuppressFailMessageInLogWindow;
     const Utils::SynchronousProcessResponse resp = synchronousGit(QString(), arguments, flags);
     QStringList branches;
+    branches << "<detached HEAD>";
+    QString headSha;
     if (resp.result == Utils::SynchronousProcessResponse::Finished) {
         // split "82bfad2f51d34e98b18982211c82220b8db049b<tab>refs/heads/master"
         foreach(const QString &line, resp.stdOut.split(QLatin1Char('\n'))) {
+            if (line.endsWith("\tHEAD")) {
+                Q_ASSERT(headSha.isNull());
+                headSha = line.left(line.indexOf(QChar('\t')));
+                continue;
+            }
+
             const int slashPos = line.lastIndexOf(QLatin1Char('/'));
-            if (slashPos != -1)
-                branches.push_back(line.mid(slashPos + 1));
+            const QString branchName = line.mid(slashPos + 1);
+            if (slashPos != -1) {
+                if (line.startsWith(headSha))
+                    branches[0] = branchName;
+                else
+                    branches.push_back(branchName);
+            }
         }
     }
     return branches;