Git: Refactor branch/HEAD access

Change-Id: I0c9955737033c0f839ac1f6ea053fecc20c24d48
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/git/gitclient.cpp

@@ -1098,64 +1098,43 @@ static inline QString msgCannotDetermineBranch(const QString &workingDirectory,
     return GitClient::tr("Cannot retrieve branch of \"%1\": %2").arg(QDir::toNativeSeparators(workingDirectory), why);
 }
 
-// Retrieve head revision/branch
+// Retrieve head branch
-bool GitClient::synchronousTopRevision(const QString &workingDirectory, QString *revision,
+QString GitClient::synchronousBranch(const QString &workingDirectory)
-                                       QString *branch, QString *errorMessageIn)
+{
+    QByteArray outputTextData;
+    QStringList arguments;
+    arguments << QLatin1String("symbolic-ref") << QLatin1String("--short") << QLatin1String("HEAD");
+    // if HEAD is detached, the command is expected to fail.
+    if (!fullySynchronousGit(workingDirectory, arguments, &outputTextData))
+        return QString();
+    QString branch = commandOutputFromLocal8Bit(outputTextData);
+    branch.remove(QLatin1Char('\n'));
+    return branch;
+}
+
+// Retrieve head revision
+QString GitClient::synchronousTopRevision(const QString &workingDirectory, QString *errorMessageIn)
 {
     QByteArray outputTextData;
     QByteArray errorText;
     QStringList arguments;
     QString errorMessage;
-    do {
     // get revision
-        if (revision) {
+    arguments << QLatin1String("rev-parse") << QLatin1String("HEAD");
-            revision->clear();
-            arguments << QLatin1String("log") << QLatin1String(noColorOption)
-                    <<  QLatin1String("--max-count=1") << QLatin1String("--pretty=format:%H");
     if (!fullySynchronousGit(workingDirectory, arguments, &outputTextData, &errorText)) {
-                errorMessage = tr("Cannot retrieve top revision of \"%1\": %2").arg(QDir::toNativeSeparators(workingDirectory), commandOutputFromLocal8Bit(errorText));
+        errorMessage = tr("Cannot retrieve top revision of \"%1\": %2")
-                break;
+                .arg(QDir::toNativeSeparators(workingDirectory), commandOutputFromLocal8Bit(errorText));
+        return QString();
     }
-            *revision = commandOutputFromLocal8Bit(outputTextData);
+    QString revision = commandOutputFromLocal8Bit(outputTextData);
-            revision->remove(QLatin1Char('\n'));
+    revision.remove(QLatin1Char('\n'));
-        } // revision desired
+    if (revision.isEmpty() && !errorMessage.isEmpty()) {
-        // get branch
+        if (errorMessageIn)
-        if (branch) {
-            branch->clear();
-            arguments.clear();
-            arguments << QLatin1String("branch") << QLatin1String(noColorOption);
-            if (!fullySynchronousGit(workingDirectory, arguments, &outputTextData, &errorText)) {
-                errorMessage = msgCannotDetermineBranch(workingDirectory, commandOutputFromLocal8Bit(errorText));
-                break;
-            }
-            /* parse output for current branch: \code
-* master
-  branch2
-\endcode */
-            const QString branchPrefix = QLatin1String("* ");
-            foreach(const QString &line, commandOutputLinesFromLocal8Bit(outputTextData)) {
-                if (line.startsWith(branchPrefix)) {
-                    *branch = line;
-                    branch->remove(0, branchPrefix.size());
-                    break;
-                }
-            }
-            if (branch->isEmpty()) {
-                errorMessage = msgCannotDetermineBranch(workingDirectory,
-                                                        QString::fromLatin1("Internal error: Failed to parse output: %1").arg(commandOutputFromLocal8Bit(outputTextData)));
-                break;
-            }
-        } // branch
-    } while (false);
-    const bool failed = (revision && revision->isEmpty()) || (branch && branch->isEmpty());
-    if (failed && !errorMessage.isEmpty()) {
-        if (errorMessageIn) {
             *errorMessageIn = errorMessage;
-        } else {
+        else
             outputWindow()->appendError(errorMessage);
     }
-    }
+    return revision;
-    return !failed;
 }
 
 // Format an entry in a one-liner for selection list using git log.

src/plugins/git/gitclient.h

@@ -160,8 +160,8 @@ public:
     QString synchronousShortDescription(const QString &workingDirectory, const QString &revision);
     QString synchronousShortDescription(const QString &workingDirectory, const QString &revision,
                                      const QString &format);
-    bool synchronousTopRevision(const QString &workingDirectory, QString *revision = 0,
+    QString synchronousBranch(const QString &workingDirectory);
-                                QString *branch = 0, QString *errorMessage = 0);
+    QString synchronousTopRevision(const QString &workingDirectory, QString *errorMessage = 0);
 
     bool cloneRepository(const QString &directory, const QByteArray &url);
     QString vcsGetRepositoryURL(const QString &directory);
@@ -266,7 +266,7 @@ private:
     bool fullySynchronousGit(const QString &workingDirectory,
                         const QStringList &arguments,
                         QByteArray* outputText,
-                        QByteArray* errorText,
+                        QByteArray* errorText = 0,
                         bool logCommandToWindow = true) const;
 
     // Synchronous git execution using Utils::SynchronousProcess, with

src/plugins/git/gitversioncontrol.cpp

@@ -161,10 +161,10 @@ QString GitVersionControl::vcsCreateSnapshot(const QString &topLevel)
         return stashMessage;
     if (repositoryUnchanged) {
         // For unchanged repository state: return identifier + top revision
-        QString topRevision;
+        QString topRevision = m_client->synchronousTopRevision(topLevel);
-        QString branch;
+        if (topRevision.isEmpty())
-        if (!m_client->synchronousTopRevision(topLevel, &topRevision, &branch))
             return QString();
+        QString branch = m_client->synchronousBranch(topLevel);
         const QChar colon = QLatin1Char(':');
         QString id = QLatin1String(stashRevisionIdC);
         id += colon;
@@ -201,9 +201,13 @@ bool GitVersionControl::vcsRestoreSnapshot(const QString &topLevel, const QStrin
                 break;
             const QString branch = tokens.at(1);
             const QString revision = tokens.at(2);
-            success = m_client->synchronousReset(topLevel)
+            success = m_client->synchronousReset(topLevel);
-                      && m_client->synchronousCheckoutBranch(topLevel, branch)
+            if (success && !branch.isEmpty()) {
-                      && m_client->synchronousCheckoutFiles(topLevel, QStringList(), revision);
+                success = m_client->synchronousCheckoutBranch(topLevel, branch) &&
+                        m_client->synchronousCheckoutFiles(topLevel, QStringList(), revision);
+            } else {
+                success = m_client->synchronousCheckoutBranch(topLevel, revision);
+            }
         } else {
             // Restore stash if it can be resolved.
             QString stashName;