gitclient.cpp

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**
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** Foundation and appearing in the file LICENSE.LGPL included in the
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#include "gitclient.h"
#include "gitcommand.h"
#include "gitutils.h"

#include "commitdata.h"
#include "gitconstants.h"
#include "gitplugin.h"
#include "gitsubmiteditor.h"
#include "gitversioncontrol.h"

#include <coreplugin/actionmanager/actionmanager.h>
#include <coreplugin/coreconstants.h>
#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/icore.h>
#include <coreplugin/messagemanager.h>
#include <coreplugin/progressmanager/progressmanager.h>
#include <coreplugin/uniqueidmanager.h>
#include <coreplugin/filemanager.h>
#include <coreplugin/iversioncontrol.h>

#include <texteditor/itexteditor.h>
#include <utils/qtcassert.h>
#include <utils/synchronousprocess.h>
#include <utils/environment.h>
#include <vcsbase/vcsbaseeditor.h>
#include <vcsbase/vcsbaseoutputwindow.h>
#include <vcsbase/vcsbaseplugin.h>

#include <QtCore/QRegExp>
#include <QtCore/QTemporaryFile>
#include <QtCore/QTime>
#include <QtCore/QFileInfo>
#include <QtCore/QDir>
#include <QtCore/QSignalMapper>

#include <QtGui/QMainWindow> // for msg box parent
#include <QtGui/QMessageBox>
#include <QtGui/QPushButton>

static const char *const kGitDirectoryC = ".git";
static const char *const kBranchIndicatorC = "# On branch";

inline Core::IEditor* locateEditor(const Core::ICore *core, const char *property, const QString &entry)
{
    foreach (Core::IEditor *ed, core->editorManager()->openedEditors())
        if (ed->file()->property(property).toString() == entry)
            return ed;
    return 0;
}

// Return converted command output, remove '\r' read on Windows
static inline QString commandOutputFromLocal8Bit(const QByteArray &a)
{
    QString output = QString::fromLocal8Bit(a);
    output.remove(QLatin1Char('\r'));
    return output;
}

// Return converted command output split into lines
static inline QStringList commandOutputLinesFromLocal8Bit(const QByteArray &a)
{
    QString output = commandOutputFromLocal8Bit(a);
    const QChar newLine = QLatin1Char('\n');
    if (output.endsWith(newLine))
        output.truncate(output.size() - 1);
    if (output.isEmpty())
        return QStringList();
    return output.split(newLine);
}

static inline VCSBase::VCSBaseOutputWindow *outputWindow()
{
    return VCSBase::VCSBaseOutputWindow::instance();
}

namespace Git {
namespace Internal {

static inline QString msgRepositoryNotFound(const QString &dir)
{
    return GitClient::tr("Unable to determine the repository for %1.").arg(dir);
}

static inline QString msgParseFilesFailed()
{
    return  GitClient::tr("Unable to parse the file output.");
}

// ---------------- GitClient

const char *GitClient::stashNamePrefix = "stash@{";

GitClient::GitClient(GitPlugin* plugin)
  : m_msgWait(tr("Waiting for data...")),
    m_plugin(plugin),
    m_core(Core::ICore::instance()),
    m_repositoryChangedSignalMapper(0),
    m_cachedGitVersion(0),
    m_hasCachedGitVersion(false)
{
    if (QSettings *s = m_core->settings()) {
        m_settings.fromSettings(s);
        m_binaryPath = m_settings.gitBinaryPath();
    }
}

GitClient::~GitClient()
{
}

const char *GitClient::noColorOption = "--no-color";

QString GitClient::findRepositoryForDirectory(const QString &dir)
{
    // Check for ".git/config"
    const QString checkFile = QLatin1String(kGitDirectoryC) + QLatin1String("/config");
    return VCSBase::VCSBasePlugin::findRepositoryForDirectory(dir, checkFile);
}

/* Create an editor associated to VCS output of a source file/directory
 * (using the file's codec). Makes use of a dynamic property to find an
 * existing instance and to reuse it (in case, say, 'git diff foo' is
 * already open). */
VCSBase::VCSBaseEditor
    *GitClient::createVCSEditor(const QString &id,
                                QString title,
                                // Source file or directory
                                const QString &source,
                                bool setSourceCodec,
                                // Dynamic property and value to identify that editor
                                const char *registerDynamicProperty,
                                const QString &dynamicPropertyValue) const
{
    VCSBase::VCSBaseEditor *rc = 0;
    Core::IEditor* outputEditor = locateEditor(m_core, registerDynamicProperty, dynamicPropertyValue);
    if (outputEditor) {
         // Exists already
        outputEditor->createNew(m_msgWait);
        rc = VCSBase::VCSBaseEditor::getVcsBaseEditor(outputEditor);
        QTC_ASSERT(rc, return 0);
    } else {
        // Create new, set wait message, set up with source and codec
        outputEditor = m_core->editorManager()->openEditorWithContents(id, &title, m_msgWait);
        outputEditor->file()->setProperty(registerDynamicProperty, dynamicPropertyValue);
        rc = VCSBase::VCSBaseEditor::getVcsBaseEditor(outputEditor);
        connect(rc, SIGNAL(annotateRevisionRequested(QString,QString,int)),
                this, SLOT(slotBlameRevisionRequested(QString,QString,int)));
        QTC_ASSERT(rc, return 0);
        rc->setSource(source);
        if (setSourceCodec)
            rc->setCodec(VCSBase::VCSBaseEditor::getCodec(source));
    }
    m_core->editorManager()->activateEditor(outputEditor, Core::EditorManager::ModeSwitch);
    rc->setForceReadOnly(true);
    return rc;
}

void GitClient::diff(const QString &workingDirectory,
                     const QStringList &diffArgs,
                     const QStringList &unstagedFileNames,
                     const QStringList &stagedFileNames)
{

    if (Git::Constants::debug)
        qDebug() << "diff" << workingDirectory << unstagedFileNames << stagedFileNames;

    const QString binary = QLatin1String(Constants::GIT_BINARY);
    const QString editorId = QLatin1String(Git::Constants::GIT_DIFF_EDITOR_ID);
    const QString title = tr("Git Diff");

    VCSBase::VCSBaseEditor *editor = createVCSEditor(editorId, title, workingDirectory, true, "originalFileName", workingDirectory);
    editor->setDiffBaseDirectory(workingDirectory);

    // Create a batch of 2 commands to be run after each other in case
    // we have a mixture of staged/unstaged files as is the case
    // when using the submit dialog.
    GitCommand *command = createCommand(workingDirectory, editor);
    // Directory diff?
    QStringList commonDiffArgs;
    commonDiffArgs << QLatin1String("diff") << QLatin1String(noColorOption);
    if (m_settings.diffPatience)
        commonDiffArgs << QLatin1String("--patience");
    if (m_settings.ignoreSpaceChanges)
        commonDiffArgs << QLatin1String("--ignore-space-change");
    if (unstagedFileNames.empty() && stagedFileNames.empty()) {
       QStringList arguments(commonDiffArgs);
       arguments << diffArgs;
       outputWindow()->appendCommand(workingDirectory, binary, arguments);
       command->addJob(arguments, m_settings.timeoutSeconds);
    } else {
        // Files diff.
        if (!unstagedFileNames.empty()) {
           QStringList arguments(commonDiffArgs);
           arguments << QLatin1String("--") << unstagedFileNames;
           outputWindow()->appendCommand(workingDirectory, binary, arguments);
           command->addJob(arguments, m_settings.timeoutSeconds);
        }
        if (!stagedFileNames.empty()) {
           QStringList arguments(commonDiffArgs);
           arguments << QLatin1String("--cached") << diffArgs << QLatin1String("--") << stagedFileNames;
           outputWindow()->appendCommand(workingDirectory, binary, arguments);
           command->addJob(arguments, m_settings.timeoutSeconds);
        }
    }
    command->execute();
}

void GitClient::diff(const QString &workingDirectory,
                     const QStringList &diffArgs,
                     const QString &fileName)
{
    if (Git::Constants::debug)
        qDebug() << "diff" << workingDirectory << fileName;
    QStringList arguments;
    arguments << QLatin1String("diff") << QLatin1String(noColorOption)
              << diffArgs;
    if (!fileName.isEmpty())
        arguments << QLatin1String("--") << fileName;
    const QString editorId = QLatin1String(Git::Constants::GIT_DIFF_EDITOR_ID);
    const QString title = tr("Git Diff %1").arg(fileName);
    const QString sourceFile = VCSBase::VCSBaseEditor::getSource(workingDirectory, fileName);
    VCSBase::VCSBaseEditor *editor = createVCSEditor(editorId, title, sourceFile, true, "originalFileName", sourceFile);
    executeGit(workingDirectory, arguments, editor);
}

void GitClient::diffBranch(const QString &workingDirectory,
                           const QStringList &diffArgs,
                           const QString &branchName)
{
    if (Git::Constants::debug)
        qDebug() << "diffBranch" << workingDirectory << branchName;
    QStringList arguments;
    arguments << QLatin1String("diff") << QLatin1String(noColorOption)
              << diffArgs  << branchName;

    const QString editorId = QLatin1String(Git::Constants::GIT_DIFF_EDITOR_ID);
    const QString title = tr("Git Diff Branch %1").arg(branchName);
    const QString sourceFile = VCSBase::VCSBaseEditor::getSource(workingDirectory, QStringList());
    VCSBase::VCSBaseEditor *editor = createVCSEditor(editorId, title, sourceFile, true,
                                                     "BranchName", branchName);
    executeGit(workingDirectory, arguments, editor);
}

void GitClient::status(const QString &workingDirectory)
{
    // @TODO: Use "--no-color" once it is supported
    QStringList statusArgs(QLatin1String("status"));
    statusArgs << QLatin1String("-u");
    VCSBase::VCSBaseOutputWindow *outwin = outputWindow();
    outwin->setRepository(workingDirectory);
    GitCommand *command = executeGit(workingDirectory, statusArgs, 0, true);
    connect(command, SIGNAL(finished(bool,int,QVariant)), outwin, SLOT(clearRepository()),
            Qt::QueuedConnection);
}

static const char graphLogFormatC[] = "%h %an %s %ci";

// Create a graphical log.
void GitClient::graphLog(const QString &workingDirectory, const QString & branch)
{
    if (Git::Constants::debug)
        qDebug() << "log" << workingDirectory;

    QStringList arguments;
    arguments << QLatin1String("log") << QLatin1String(noColorOption);

    if (m_settings.logCount > 0)
         arguments << QLatin1String("-n") << QString::number(m_settings.logCount);
    arguments << (QLatin1String("--pretty=format:") +  QLatin1String(graphLogFormatC))
              << QLatin1String("--topo-order") <<  QLatin1String("--graph");

    QString title;
    if (branch.isEmpty()) {
        title = tr("Git Log");
    } else {
        title = tr("Git Log %1").arg(branch);
        arguments << branch;
    }
    const QString editorId = QLatin1String(Git::Constants::GIT_LOG_EDITOR_ID);
    const QString sourceFile = VCSBase::VCSBaseEditor::getSource(workingDirectory, QStringList());
    VCSBase::VCSBaseEditor *editor = createVCSEditor(editorId, title, sourceFile, false, "logFileName", sourceFile);
    executeGit(workingDirectory, arguments, editor);
}

void GitClient::log(const QString &workingDirectory, const QStringList &fileNames, bool enableAnnotationContextMenu)
{
    if (Git::Constants::debug)
        qDebug() << "log" << workingDirectory << fileNames;

    QStringList arguments;
    arguments << QLatin1String("log") << QLatin1String(noColorOption);

    if (m_settings.logCount > 0)
         arguments << QLatin1String("-n") << QString::number(m_settings.logCount);

    if (!fileNames.isEmpty())
        arguments.append(fileNames);

    const QString msgArg = fileNames.empty() ? workingDirectory :
                           fileNames.join(QString(", "));
    const QString title = tr("Git Log %1").arg(msgArg);
    const QString editorId = QLatin1String(Git::Constants::GIT_LOG_EDITOR_ID);
    const QString sourceFile = VCSBase::VCSBaseEditor::getSource(workingDirectory, fileNames);
    VCSBase::VCSBaseEditor *editor = createVCSEditor(editorId, title, sourceFile, false, "logFileName", sourceFile);
    editor->setFileLogAnnotateEnabled(enableAnnotationContextMenu);
    executeGit(workingDirectory, arguments, editor);
}

// Do not show "0000" or "^32ae4"
static inline bool canShow(const QString &sha)
{
    if (sha.startsWith(QLatin1Char('^')))
        return false;
    if (sha.count(QLatin1Char('0')) == sha.size())
        return false;
    return true;
}

static inline QString msgCannotShow(const QString &sha)
{
    return GitClient::tr("Cannot describe '%1'.").arg(sha);
}

void GitClient::show(const QString &source, const QString &id)
{
    if (Git::Constants::debug)
        qDebug() << "show" << source << id;
    if (!canShow(id)) {
        outputWindow()->append(msgCannotShow(id));
        return;
    }

    QStringList arguments;
    arguments << QLatin1String("show") << QLatin1String(noColorOption) << id;

    const QString title =  tr("Git Show %1").arg(id);
    const QString editorId = QLatin1String(Git::Constants::GIT_DIFF_EDITOR_ID);
    VCSBase::VCSBaseEditor *editor = createVCSEditor(editorId, title, source, true, "show", id);

    const QFileInfo sourceFi(source);
    const QString workDir = sourceFi.isDir() ? sourceFi.absoluteFilePath() : sourceFi.absolutePath();
    executeGit(workDir, arguments, editor);
}

void GitClient::slotBlameRevisionRequested(const QString &source, QString change, int lineNumber)
{
    // This might be invoked with a verbose revision description
    // "SHA1 author subject" from the annotation context menu. Strip the rest.
    const int blankPos = change.indexOf(QLatin1Char(' '));
    if (blankPos != -1)
        change.truncate(blankPos);
    const QFileInfo fi(source);
    blame(fi.absolutePath(), fi.fileName(), change, lineNumber);
}

void GitClient::blame(const QString &workingDirectory,
                      const QString &fileName,
                      const QString &revision /* = QString() */,
                      int lineNumber /* = -1 */)
{
    if (Git::Constants::debug)
        qDebug() << "blame" << workingDirectory << fileName << lineNumber;
    QStringList arguments(QLatin1String("blame"));
    arguments << QLatin1String("--root");
    if (m_plugin->settings().ignoreSpaceChanges)
        arguments << QLatin1String("-w");
    arguments << QLatin1String("--") << fileName;
    if (!revision.isEmpty())
        arguments << revision;
    const QString editorId = QLatin1String(Git::Constants::GIT_BLAME_EDITOR_ID);
    const QString id = VCSBase::VCSBaseEditor::getTitleId(workingDirectory, QStringList(fileName), revision);
    const QString title = tr("Git Blame %1").arg(id);
    const QString sourceFile = VCSBase::VCSBaseEditor::getSource(workingDirectory, fileName);

    VCSBase::VCSBaseEditor *editor = createVCSEditor(editorId, title, sourceFile, true, "blameFileName", id);
    executeGit(workingDirectory, arguments, editor, false, GitCommand::NoReport, lineNumber);
}

void GitClient::checkoutBranch(const QString &workingDirectory, const QString &branch)
{
    QStringList arguments(QLatin1String("checkout"));
    arguments <<  branch;
    GitCommand *cmd = executeGit(workingDirectory, arguments, 0, true);
    connectRepositoryChanged(workingDirectory, cmd);
}

bool GitClient::synchronousCheckoutBranch(const QString &workingDirectory,
                                    const QString &branch,
                                    QString *errorMessage /* = 0 */)
{
    QByteArray outputText;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("checkout") << branch;
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    const QString output = commandOutputFromLocal8Bit(outputText);
    outputWindow()->append(output);
    if (!rc) {
        const QString stdErr = commandOutputFromLocal8Bit(errorText);
        //: Meaning of the arguments: %1: Branch, %2: Repository, %3: Error message
        const QString msg = tr("Unable to checkout %1 of %2: %3").arg(branch, workingDirectory, stdErr);
        if (errorMessage) {
            *errorMessage = msg;
        } else {
            outputWindow()->appendError(msg);
        }
        return false;
    }
    return true;
}

void GitClient::checkout(const QString &workingDirectory, const QString &fileName)
{
    // Passing an empty argument as the file name is very dangereous, since this makes
    // git checkout apply to all files. Almost looks like a bug in git.
    if (fileName.isEmpty())
        return;

    QStringList arguments;
    arguments << QLatin1String("checkout") << QLatin1String("HEAD") << QLatin1String("--")
            << fileName;

    executeGit(workingDirectory, arguments, 0, true);
}

void GitClient::hardReset(const QString &workingDirectory, const QString &commit)
{
    QStringList arguments;
    arguments << QLatin1String("reset") << QLatin1String("--hard");
    if (!commit.isEmpty())
        arguments << commit;

    GitCommand *cmd = executeGit(workingDirectory, arguments, 0, true);
    connectRepositoryChanged(workingDirectory, cmd);
}

void GitClient::addFile(const QString &workingDirectory, const QString &fileName)
{
    QStringList arguments;
    arguments << QLatin1String("add") << fileName;

    executeGit(workingDirectory, arguments, 0, true);
}

// Warning: 'intendToAdd' works only from 1.6.1 onwards
bool GitClient::synchronousAdd(const QString &workingDirectory,
                               bool intendToAdd,
                               const QStringList &files)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << files;
    QByteArray outputText;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("add");
    if (intendToAdd)
        arguments << QLatin1String("--intent-to-add");
    arguments.append(files);
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    if (!rc) {
        const QString errorMessage = tr("Unable to add %n file(s) to %1: %2", 0, files.size()).
                                     arg(QDir::toNativeSeparators(workingDirectory),
                                     commandOutputFromLocal8Bit(errorText));
        outputWindow()->appendError(errorMessage);
    }
    return rc;
}

bool GitClient::synchronousDelete(const QString &workingDirectory,
                                  bool force,
                                  const QStringList &files)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << files;
    QByteArray outputText;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("rm");
    if (force)
        arguments << QLatin1String("--force");
    arguments.append(files);
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    if (!rc) {
        const QString errorMessage = tr("Unable to remove %n file(s) from %1: %2", 0, files.size()).
                                     arg(QDir::toNativeSeparators(workingDirectory), commandOutputFromLocal8Bit(errorText));
        outputWindow()->appendError(errorMessage);
    }
    return rc;
}

bool GitClient::synchronousMove(const QString &workingDirectory,
                                const QString &from,
                                const QString &to)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << from << to;
    QByteArray outputText;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("mv");
    arguments << (from);
    arguments << (to);
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    if (!rc) {
        const QString errorMessage = tr("Unable to move from %1 to %2: %3").
                                     arg(from, to, commandOutputFromLocal8Bit(errorText));
        outputWindow()->appendError(errorMessage);
    }
    return rc;
}

bool GitClient::synchronousReset(const QString &workingDirectory,
                                 const QStringList &files,
                                 QString *errorMessage)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << files;
    QByteArray outputText;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("reset");
    if (files.isEmpty()) {
        arguments << QLatin1String("--hard");
    } else {
        arguments << QLatin1String("HEAD") << QLatin1String("--") << files;
    }
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    const QString output = commandOutputFromLocal8Bit(outputText);
    outputWindow()->append(output);
    // Note that git exits with 1 even if the operation is successful
    // Assume real failure if the output does not contain "foo.cpp modified"
    // or "Unstaged changes after reset" (git 1.7.0).
    if (!rc &&
        (!output.contains(QLatin1String("modified"))
         && !output.contains(QLatin1String("Unstaged changes after reset")))) {
        const QString stdErr = commandOutputFromLocal8Bit(errorText);
        const QString msg = files.isEmpty() ?
                            tr("Unable to reset %1: %2").arg(QDir::toNativeSeparators(workingDirectory), stdErr) :
                            tr("Unable to reset %n file(s) in %1: %2", 0, files.size()).
                            arg(QDir::toNativeSeparators(workingDirectory), stdErr);
        if (errorMessage) {
            *errorMessage = msg;
        } else {
            outputWindow()->appendError(msg);
        }
        return false;
    }
    return true;
}

// Initialize repository
bool GitClient::synchronousInit(const QString &workingDirectory)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory;
    QByteArray outputText;
    QByteArray errorText;
    const QStringList arguments(QLatin1String("init"));
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    // '[Re]Initialized...'
    outputWindow()->append(commandOutputFromLocal8Bit(outputText));
    if (!rc)
        outputWindow()->appendError(commandOutputFromLocal8Bit(errorText));
    return rc;
}

/* Checkout, supports:
 * git checkout -- <files>
 * git checkout revision -- <files>
 * git checkout revision -- . */
bool GitClient::synchronousCheckoutFiles(const QString &workingDirectory,
                                         QStringList files /* = QStringList() */,
                                         QString revision /* = QString() */,
                                         QString *errorMessage /* = 0 */,
                                         bool revertStaging /* = true */)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << files;
    if (revertStaging && revision.isEmpty())
        revision = QLatin1String("HEAD");
    if (files.isEmpty())
        files = QStringList(QString(QLatin1Char('.')));
    QByteArray outputText;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("checkout");
    if (revertStaging)
        arguments << revision;
    arguments << QLatin1String("--") << files;
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    if (!rc) {
        const QString fileArg = files.join(QLatin1String(", "));
        //: Meaning of the arguments: %1: revision, %2: files, %3: repository,
        //: %4: Error message
        const QString msg = tr("Unable to checkout %1 of %2 in %3: %4").
                            arg(revision, fileArg, workingDirectory, commandOutputFromLocal8Bit(errorText));
        if (errorMessage) {
            *errorMessage = msg;
        } else {
            outputWindow()->appendError(msg);
        }
        return false;
    }
    return true;
}

static inline QString msgParentRevisionFailed(const QString &workingDirectory,
                                              const QString &revision,
                                              const QString &why)
{
    //: Failed to find parent revisions of a SHA1 for "annotate previous"
    return GitClient::tr("Unable to find parent revisions of %1 in %2: %3").arg(revision, workingDirectory, why);
}

static inline QString msgInvalidRevision()
{
    return GitClient::tr("Invalid revision");
}

// Split a line of "<commit> <parent1> ..." to obtain parents from "rev-list" or "log".
static inline bool splitCommitParents(const QString &line,
                                      QString *commit = 0,
                                      QStringList *parents = 0)
{
    if (commit)
        commit->clear();
    if (parents)
        parents->clear();
    QStringList tokens = line.trimmed().split(QLatin1Char(' '));
    if (tokens.size() < 2)
        return false;
    if (commit)
        *commit = tokens.front();
    tokens.pop_front();
    if (parents)
        *parents = tokens;
    return true;
}

// Find out the immediate parent revisions of a revision of the repository.
// Might be several in case of merges.
bool GitClient::synchronousParentRevisions(const QString &workingDirectory,
                                           const QStringList &files /* = QStringList() */,
                                           const QString &revision,
                                           QStringList *parents,
                                           QString *errorMessage)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << revision;
    QByteArray outputTextData;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("rev-list") << QLatin1String(GitClient::noColorOption)
              << QLatin1String("--parents") << QLatin1String("--max-count=1") << revision;
    if (!files.isEmpty()) {
        arguments.append(QLatin1String("--"));
        arguments.append(files);
    }
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputTextData, &errorText);
    if (!rc) {
        *errorMessage = msgParentRevisionFailed(workingDirectory, revision, commandOutputFromLocal8Bit(errorText));
        return false;
    }
    // Should result in one line of blank-delimited revisions, specifying current first
    // unless it is top.
    QString outputText = commandOutputFromLocal8Bit(outputTextData);
    outputText.remove(QLatin1Char('\n'));
    if (!splitCommitParents(outputText, 0, parents)) {
        *errorMessage = msgParentRevisionFailed(workingDirectory, revision, msgInvalidRevision());
        return false;
    }
    if (Git::Constants::debug)
        qDebug() << workingDirectory << files << revision << "->" << *parents;
    return true;
}

// Short SHA1, author, subject
static const char defaultShortLogFormatC[] = "%h (%an \"%s\")";

bool GitClient::synchronousShortDescription(const QString &workingDirectory, const QString &revision,
                                    QString *description, QString *errorMessage)
{
    // Short SHA 1, author, subject
    return synchronousShortDescription(workingDirectory, revision,
                               QLatin1String(defaultShortLogFormatC),
                               description, errorMessage);
}

// Convenience working on a list of revisions
bool GitClient::synchronousShortDescriptions(const QString &workingDirectory, const QStringList &revisions,
                                            QStringList *descriptions, QString *errorMessage)
{
    descriptions->clear();
    foreach (const QString &revision, revisions) {
        QString description;
        if (!synchronousShortDescription(workingDirectory, revision, &description, errorMessage)) {
            descriptions->clear();
            return false;
        }
        descriptions->push_back(description);
    }
    return true;
}

static inline QString msgCannotDetermineBranch(const QString &workingDirectory, const QString &why)
{
    return GitClient::tr("Unable to retrieve branch of %1: %2").arg(QDir::toNativeSeparators(workingDirectory), why);
}

// Retrieve head revision/branch
bool GitClient::synchronousTopRevision(const QString &workingDirectory,
                                       QString *revision /* = 0 */,
                                       QString *branch /* = 0 */,
                                       QString *errorMessageIn /* = 0 */)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory;
    QByteArray outputTextData;
    QByteArray errorText;
    QStringList arguments;
    QString errorMessage;
    do {
        // get revision
        if (revision) {
            revision->clear();
            arguments << QLatin1String("log") << QLatin1String(noColorOption)
                    <<  QLatin1String("--max-count=1") << QLatin1String("--pretty=format:%H");
            if (!fullySynchronousGit(workingDirectory, arguments, &outputTextData, &errorText)) {
                errorMessage =  tr("Unable to retrieve top revision of %1: %2").arg(QDir::toNativeSeparators(workingDirectory), commandOutputFromLocal8Bit(errorText));
                break;
            }
            *revision = commandOutputFromLocal8Bit(outputTextData);
            revision->remove(QLatin1Char('\n'));
        } // revision desired
        // get branch
        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 {
            outputWindow()->appendError(errorMessage);
        }
    }
    return !failed;
}

// Format an entry in a one-liner for selection list using git log.
bool GitClient::synchronousShortDescription(const QString &workingDirectory,
                                    const QString &revision,
                                    const QString &format,
                                    QString *description,
                                    QString *errorMessage)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << revision;
    QByteArray outputTextData;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("log") << QLatin1String(GitClient::noColorOption)
              << (QLatin1String("--pretty=format:") + format)
              << QLatin1String("--max-count=1") << revision;
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputTextData, &errorText);
    if (!rc) {
        *errorMessage = tr("Unable to describe revision %1 in %2: %3").arg(revision, workingDirectory, commandOutputFromLocal8Bit(errorText));
        return false;
    }
    *description = commandOutputFromLocal8Bit(outputTextData);
    if (description->endsWith(QLatin1Char('\n')))
        description->truncate(description->size() - 1);
    return true;
}

// Create a default message to be used for describing stashes
static inline QString creatorStashMessage(const QString &keyword = QString())
{
    QString rc = QCoreApplication::applicationName();
    rc += QLatin1Char(' ');
    if (!keyword.isEmpty()) {
        rc += keyword;
        rc += QLatin1Char(' ');
    }
    rc += QDateTime::currentDateTime().toString(Qt::ISODate);
    return rc;
}

/* Do a stash and return the message as identifier. Note that stash names (stash{n})
 * shift as they are pushed, so, enforce the use of messages to identify them. Flags:
 * StashPromptDescription: Prompt the user for a description message.
 * StashImmediateRestore: Immediately re-apply this stash (used for snapshots), user keeps on working
 * StashIgnoreUnchanged: Be quiet about unchanged repositories (used for IVersionControl's snapshots). */

QString GitClient::synchronousStash(const QString &workingDirectory,
                                    const QString &messageKeyword /*  = QString() */,
                                    unsigned flags,
                                    bool *unchanged /* =0 */)
{
    if (unchanged)
        *unchanged = false;
    QString message;
    bool success = false;
    // Check for changes and stash
    QString errorMessage;
    switch (gitStatus(workingDirectory, false, 0, &errorMessage)) {
    case  StatusChanged: {
            message = creatorStashMessage(messageKeyword);
            do {
                if ((flags & StashPromptDescription)) {
                    if (!inputText(Core::ICore::instance()->mainWindow(),
                         tr("Stash Description"), tr("Description:"), &message))
                        break;
                }
                if (!executeSynchronousStash(workingDirectory, message))
                    break;
                if ((flags & StashImmediateRestore)
                    && !synchronousStashRestore(workingDirectory, QLatin1String("stash@{0}")))
                    break;
                success = true;
            } while (false);
        }
        break;
    case StatusUnchanged:
        if (unchanged)
            *unchanged = true;
        if (!(flags & StashIgnoreUnchanged))
            outputWindow()->append(msgNoChangedFiles());
        break;
    case StatusFailed:
        outputWindow()->append(errorMessage);
        break;
    }
    if (!success)
        message.clear();
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << '\n' << workingDirectory << messageKeyword << "returns" << message;
    return message;
}

bool GitClient::executeSynchronousStash(const QString &workingDirectory,
                                 const QString &message,
                                 QString *errorMessage /* = 0*/)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory;
    QByteArray outputText;
    QByteArray errorText;
    QStringList arguments;
    arguments << QLatin1String("stash");
    if (!message.isEmpty())
        arguments << QLatin1String("save") << message;
    const bool rc = fullySynchronousGit(workingDirectory, arguments, &outputText, &errorText);
    if (!rc) {
        const QString msg = tr("Unable stash in %1: %2").
                            arg(QDir::toNativeSeparators(workingDirectory),
                                commandOutputFromLocal8Bit(errorText));
        if (errorMessage) {
            *errorMessage = msg;
        } else {
            outputWindow()->append(msg);
        }
        return false;
    }
    return true;
}

// Resolve a stash name from message
bool GitClient::stashNameFromMessage(const QString &workingDirectory,
                                     const QString &message, QString *name,
                                     QString *errorMessage /* = 0 */)
{
    // All happy
    if (message.startsWith(QLatin1String(stashNamePrefix))) {
        *name = message;
        return true;
    }
    // Retrieve list and find via message
    QList<Stash> stashes;
    if (!synchronousStashList(workingDirectory, &stashes, errorMessage))
        return false;
    foreach (const Stash &s, stashes) {
        if (s.message == message) {
            *name = s.name;
            return true;
        }
    }
    //: Look-up of a stash via its descriptive message failed.
    const QString msg = tr("Unable to resolve stash message '%1' in %2").arg(message, workingDirectory);
    if (errorMessage) {
        *errorMessage = msg;
    } else {
        outputWindow()->append(msg);
    }
    return  false;
}

bool GitClient::synchronousBranchCmd(const QString &workingDirectory, QStringList branchArgs,
                                     QString *output, QString *errorMessage)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << branchArgs;
    branchArgs.push_front(QLatin1String("branch"));
    QByteArray outputText;
    QByteArray errorText;
    const bool rc = fullySynchronousGit(workingDirectory, branchArgs, &outputText, &errorText);
    if (!rc) {
        *errorMessage = tr("Unable to run a 'git branch' command in %1: %2").arg(QDir::toNativeSeparators(workingDirectory), commandOutputFromLocal8Bit(errorText));
        return false;
    }
    *output = commandOutputFromLocal8Bit(outputText);
    return true;
}

bool GitClient::synchronousShow(const QString &workingDirectory, const QString &id,
                                 QString *output, QString *errorMessage)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory << id;
    if (!canShow(id)) {
        *errorMessage = msgCannotShow(id);
        return false;
    }
    QStringList args(QLatin1String("show"));
    args << QLatin1String(noColorOption) << id;
    QByteArray outputText;
    QByteArray errorText;
    const bool rc = fullySynchronousGit(workingDirectory, args, &outputText, &errorText);
    if (!rc) {
        *errorMessage = tr("Unable to run 'git show' in %1: %2").arg(QDir::toNativeSeparators(workingDirectory), commandOutputFromLocal8Bit(errorText));
        return false;
    }
    *output = commandOutputFromLocal8Bit(outputText);
    return true;
}

// Retrieve list of files to be cleaned
bool GitClient::synchronousCleanList(const QString &workingDirectory,
                                     QStringList *files, QString *errorMessage)
{
    if (Git::Constants::debug)
        qDebug() << Q_FUNC_INFO << workingDirectory;
    files->clear();
    QStringList args;
    args << QLatin1String("clean") << QLatin1String("--dry-run") << QLatin1String("-dxf");
    QByteArray outputText;
    QByteArray errorText;