Fix some code scanning issues.

QString: Use QChar/char where appropriate, do not use QString::null

src/plugins/cmakeprojectmanager/cmakeproject.cpp

@@ -984,10 +984,10 @@ QString CMakeCbpParser::compilerName() const
 
 void CMakeBuildTarget::clear()
 {
-    executable = QString::null;
+    executable.clear();
-    makeCommand = QString::null;
+    makeCommand.clear();
-    makeCleanCommand = QString::null;
+    makeCleanCommand.clear();
-    workingDirectory = QString::null;
+    workingDirectory.clear();
-    title = QString::null;
+    title.clear();
 }
 

src/plugins/cmakeprojectmanager/cmakeprojectmanager.cpp

@@ -131,7 +131,7 @@ QString CMakeManager::findCbpFile(const QDir &directory)
         if (cbpFile.endsWith(QLatin1String(".cbp")))
             return directory.path() + QLatin1Char('/') + cbpFile;
     }
-    return QString::null;
+    return QString();
 }
 
 // This code is duplicated from qtversionmanager

src/plugins/debugger/gdb/gdbmi.cpp

@@ -308,33 +308,33 @@ QByteArray GdbMi::toString(bool multiline, int indent) const
             break;
         case Const:
             if (!m_name.isEmpty())
-                result += m_name + "=";
+                result += m_name + '=';
-            result += "\"" + escapeCString(m_data) + "\"";
+            result += '"' + escapeCString(m_data) + '"';
             break;
         case Tuple:
             if (!m_name.isEmpty())
-                result += m_name + "=";
+                result += m_name + '=';
             if (multiline) {
                 result += "{\n";
                 dumpChildren(&result, multiline, indent + 1);
-                result += '\n' + ind(indent) + "}";
+                result += '\n' + ind(indent) + '}';
             } else {
-                result += "{";
+                result += '{';
                 dumpChildren(&result, multiline, indent + 1);
-                result += "}";
+                result += '}';
             }
             break;
         case List:
             if (!m_name.isEmpty())
-                result += m_name + "=";
+                result += m_name + '=';
             if (multiline) {
                 result += "[\n";
                 dumpChildren(&result, multiline, indent + 1);
-                result += '\n' + ind(indent) + "]";
+                result += '\n' + ind(indent) + ']';
             } else {
-                result += "[";
+                result += '[';
                 dumpChildren(&result, multiline, indent + 1);
-                result += "]";
+                result += ']';
             }
             break;
     }

src/plugins/designer/formwindoweditor.cpp

@@ -371,7 +371,7 @@ QString FormWindowEditor::contextHelpId() const
 QString FormWindowEditor::contents() const
 {
     if (!m_formWindow)
-        return QString::null;
+        return QString();
 //  Activate once all Qt branches around have integrated 4.5.2
 //  (Kinetic)
 /*

src/plugins/fakevim/fakevimhandler.cpp

@@ -885,7 +885,7 @@ void FakeVimHandler::Private::finishMovement(const QString &dotCommand)
     if (m_submode == ChangeSubMode) {
         removeSelectedText(true);
         if (!dotCommand.isEmpty())
-            setDotCommand("c" + dotCommand);
+            setDotCommand(QLatin1Char('c') + dotCommand);
         if (m_movetype == MoveLineWise) {
             insertAutomaticIndentation(true);
         }
@@ -896,7 +896,7 @@ void FakeVimHandler::Private::finishMovement(const QString &dotCommand)
     } else if (m_submode == DeleteSubMode) {
         removeSelectedText();
         if (!dotCommand.isEmpty())
-            setDotCommand("d" + dotCommand);
+            setDotCommand(QLatin1Char('d') + dotCommand);
         if (m_movetype == MoveLineWise)
             handleStartOfLine();
         m_submode = NoSubMode;
@@ -922,7 +922,7 @@ void FakeVimHandler::Private::finishMovement(const QString &dotCommand)
         if (m_subsubmode == InvertCaseSubSubMode) {
             invertCaseSelectedText();
             if (!dotCommand.isEmpty())
-                setDotCommand("~" + dotCommand);
+                setDotCommand(QLatin1Char('~') + dotCommand);
         } else if (m_subsubmode == UpCaseSubSubMode) {
             upCaseSelectedText();
             if (!dotCommand.isEmpty())
@@ -1204,7 +1204,7 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
         // Recognize ZZ and ZQ as aliases for ":x" and ":q!".
         m_submode = NoSubMode;
         if (key == 'Z')
-            handleCommand("x");
+            handleCommand(QString(QLatin1Char('x')));
         else if (key == 'Q')
             handleCommand("q!");
     } else if (m_subsubmode == FtSubSubMode) {
@@ -1251,14 +1251,14 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
             m_movetype = MoveExclusive;
             moveToStartOfLine();
             setTargetColumn();
-            finishMovement("0");
+            finishMovement(QString(QLatin1Char('0')));
         } else {
             m_mvcount.append(QChar(key));
         }
     } else if (key == '^') {
         moveToFirstNonBlankOnLine();
         m_movetype = MoveExclusive;
-        finishMovement("^");
+        finishMovement(QString(QLatin1Char('^')));
     } else if (0 && key == ',') {
         // FIXME: fakevim uses ',' by itself, so it is incompatible
         m_subsubmode = FtSubSubMode;
@@ -1403,7 +1403,7 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
     } else if (key == 'A') {
         enterInsertMode();
         moveBehindEndOfLine();
-        setDotCommand("A");
+        setDotCommand(QString(QLatin1Char('A')));
         m_lastInsertion.clear();
         updateMiniBuffer();
     } else if (key == control('a')) {
@@ -1433,7 +1433,7 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
         setAnchor();
         moveToEndOfLine();
         m_submode = ChangeSubMode;
-        setDotCommand("C");
+        setDotCommand(QString(QLatin1Char('C')));
         finishMovement();
     } else if (key == control('c')) {
         if (isNoVisualMode())
@@ -1476,7 +1476,7 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
         moveDown(qMax(count() - 1, 0));
         m_movetype = MoveInclusive;
         moveToEndOfLine();
-        setDotCommand("D");
+        setDotCommand(QString(QLatin1Char('D')));
         finishMovement();
     } else if ((key == 'D' || key == 'X') &&
          (isVisualCharMode() || isVisualLineMode())) {
@@ -1526,7 +1526,7 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
     } else if (key == 'g' || key == 'G') {
         QString dotCommand = QString("%1G").arg(count());
         if (key == 'G' && m_mvcount.isEmpty())
-            dotCommand = "G";
+            dotCommand = QString(QLatin1Char('G'));
         if (key == 'g')
             m_gflag = false;
         int n = (key == 'g') ? 1 : linesInDocument();
@@ -1557,13 +1557,13 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
         handleStartOfLine();
         finishMovement();
     } else if (key == 'i' || key == Key_Insert) {
-        setDotCommand("i"); // setDotCommand("%1i", count());
+        setDotCommand(QString(QLatin1Char('i'))); // setDotCommand("%1i", count());
         enterInsertMode();
         updateMiniBuffer();
         if (atEndOfLine())
             moveLeft();
     } else if (key == 'I') {
-        setDotCommand("I"); // setDotCommand("%1I", count());
+        setDotCommand(QString(QLatin1Char('I'))); // setDotCommand("%1I", count());
         enterInsertMode();
         if (m_gflag)
             moveToStartOfLine();
@@ -1597,7 +1597,7 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
                         || characterAtCursor() == '\t')
                         moveRight();
                     removeSelectedText();
-                    m_tc.insertText(" ");
+                    m_tc.insertText(QString(QLatin1Char(' ')));
                 }
             }
             if (!m_gflag)
@@ -1685,14 +1685,14 @@ EventResult FakeVimHandler::Private::handleCommandMode(int key, int unmodified,
         finishMovement();
     } else if (key == 'r') {
         m_submode = ReplaceSubMode;
-        setDotCommand("r");
+        setDotCommand(QString(QLatin1Char('r')));
     } else if (key == 'R') {
         // FIXME: right now we repeat the insertion count() times,
         // but not the deletion
         m_lastInsertion.clear();
         enterInsertMode();
         m_submode = ReplaceSubMode;
-        setDotCommand("R");
+        setDotCommand(QString(QLatin1Char('R')));
         updateMiniBuffer();
     } else if (key == control('r')) {
         redo();

src/plugins/git/changeselectiondialog.cpp

@@ -60,7 +60,7 @@ void ChangeSelectionDialog::setRepository(const QString &s)
 
 void ChangeSelectionDialog::selectWorkingDirectory()
 {
-    static QString location = QString();
+    static QString location;
     location = QFileDialog::getExistingDirectory(this,
                                       tr("Select Git repository"),
                                       location);

src/plugins/locator/basefilefilter.cpp

@@ -49,10 +49,11 @@ QList<FilterEntry> BaseFileFilter::matchesFor(const QString &origEntry)
     QList<FilterEntry> badMatches;
     QString needle = trimWildcards(origEntry);
     QStringMatcher matcher(needle, Qt::CaseInsensitive);
-    const QRegExp regexp("*"+needle+"*", Qt::CaseInsensitive, QRegExp::Wildcard);
+    const QChar asterisk = QLatin1Char('*');
+    const QRegExp regexp(asterisk + needle+ asterisk, Qt::CaseInsensitive, QRegExp::Wildcard);
     if (!regexp.isValid())
         return matches;
-    bool hasWildcard = (needle.contains('*') || needle.contains('?'));
+    bool hasWildcard = (needle.contains(asterisk) || needle.contains('?'));
     QStringList searchListPaths;
     QStringList searchListNames;
     if (!m_previousEntry.isEmpty() && !m_forceNewSearchList && needle.contains(m_previousEntry)) {

src/plugins/locator/locatorfiltersfilter.cpp

@@ -85,7 +85,7 @@ void LocatorFiltersFilter::accept(FilterEntry selection) const
 {
     ILocatorFilter *filter = selection.internalData.value<ILocatorFilter*>();
     if (filter)
-        m_locatorWidget->show(filter->shortcutString() + " ",
+        m_locatorWidget->show(filter->shortcutString() + QLatin1Char(' '),
                            filter->shortcutString().length() + 1);
 }
 

src/plugins/perforce/perforceplugin.cpp

@@ -1307,7 +1307,7 @@ QString PerforcePlugin::clientFilePath(const QString &serverFilePath)
     const PerforceResponse response = runP4Cmd(m_settings.topLevelSymLinkTarget(), args,
                                                ShowBusyCursor|RunFullySynchronous|CommandToWindow|StdErrToWindow|ErrorToWindow);
     if (response.error)
-        return QString::null;
+        return QString();
 
     QRegExp r(QLatin1String("\\.\\.\\.\\sclientFile\\s(.+)\n"));
     r.setMinimal(true);
@@ -1325,19 +1325,19 @@ QString PerforcePlugin::pendingChangesData()
     const PerforceResponse userResponse = runP4Cmd(m_settings.topLevelSymLinkTarget(), args,
                                                RunFullySynchronous|CommandToWindow|StdErrToWindow|ErrorToWindow);
     if (userResponse.error)
-        return QString::null;
+        return QString();
 
     QRegExp r(QLatin1String("User\\sname:\\s(\\S+)\\s*\n"));
     QTC_ASSERT(r.isValid(), return QString())
     r.setMinimal(true);
-    const QString user = r.indexIn(userResponse.stdOut) != -1 ? r.cap(1).trimmed() : QString::null;
+    const QString user = r.indexIn(userResponse.stdOut) != -1 ? r.cap(1).trimmed() : QString();
     if (user.isEmpty())
-        return QString::null;
+        return QString();
     args.clear();
     args << QLatin1String("changes") << QLatin1String("-s") << QLatin1String("pending") << QLatin1String("-u") << user;
     const PerforceResponse dataResponse = runP4Cmd(m_settings.topLevelSymLinkTarget(), args,
                                                    RunFullySynchronous|CommandToWindow|StdErrToWindow|ErrorToWindow);
-    return dataResponse.error ? QString::null : dataResponse.stdOut;
+    return dataResponse.error ? QString() : dataResponse.stdOut;
 }
 
 PerforcePlugin::~PerforcePlugin()

src/plugins/perforce/settingspage.cpp

@@ -101,7 +101,7 @@ void SettingsPageWidget::setSettings(const PerforceSettings &s)
 
 void SettingsPageWidget::setStatusText(const QString &t)
 {
-    m_ui.errorLabel->setStyleSheet(QString::null);
+    m_ui.errorLabel->setStyleSheet(QString());
     m_ui.errorLabel->setText(t);
 }
 

src/plugins/projectexplorer/customexecutablerunconfiguration.cpp

@@ -398,7 +398,7 @@ QString CustomExecutableRunConfiguration::baseEnvironmentText() const
     } else  if (m_baseEnvironmentBase == CustomExecutableRunConfiguration::BuildEnvironmentBase) {
         return tr("Build Environment");
     }
-    return QString::null;
+    return QString();
 }
 
 ProjectExplorer::Environment CustomExecutableRunConfiguration::baseEnvironment() const

src/plugins/projectexplorer/debugginghelper.cpp

@@ -54,7 +54,7 @@ QString DebuggingHelperLibrary::findSystemQt(const Environment &env)
             }
         }
     }
-    return QString::null;
+    return QString();
 }
 
 QStringList DebuggingHelperLibrary::debuggingHelperLibraryDirectories(const QString &qtInstallData)
@@ -75,7 +75,7 @@ QString DebuggingHelperLibrary::qtInstallDataDir(const QString &qmakePath)
     proc.start(qmakePath, QStringList() << QLatin1String("-query") << QLatin1String("QT_INSTALL_DATA"));
     if (proc.waitForFinished())
         return QString(proc.readAll().trimmed());
-    return QString::null;
+    return QString();
 }
 
 // Debugging Helper Library
@@ -136,7 +136,7 @@ QString DebuggingHelperLibrary::buildDebuggingHelperLibrary(const QString &qmake
     const QString directory = copyDebuggingHelperLibrary(qtInstallDataDir(qmakePath), &errorMessage);
     if (directory.isEmpty())
         return errorMessage;
-    return buildDebuggingHelperLibrary(directory, make, qmakePath, QString::null, env);
+    return buildDebuggingHelperLibrary(directory, make, qmakePath, QString(), env);
 }
 
 // Copy helper source files to a target directory, replacing older files.
@@ -245,7 +245,7 @@ QString DebuggingHelperLibrary::qtVersionForQMake(const QString &qmakePath)
     QProcess qmake;
     qmake.start(qmakePath, QStringList(QLatin1String("--version")));
     if (!qmake.waitForFinished())
-        return QString::null;
+        return QString();
     QString output = qmake.readAllStandardOutput();
     QRegExp regexp(QLatin1String("(QMake version|QMake version:)[\\s]*([\\d.]*)"), Qt::CaseInsensitive);
     regexp.indexIn(output);

src/plugins/projectexplorer/environment.cpp

@@ -183,7 +183,7 @@ QString Environment::searchInPath(QString executable) const
 {
 //    qDebug()<<"looking for "<<executable<< "in PATH: "<<m_values.value("PATH");
     if (executable.isEmpty())
-        return QString::null;
+        return QString();
     QFileInfo fi(executable);
     if (fi.isAbsolute() && fi.exists())
         return executable;
@@ -203,7 +203,7 @@ QString Environment::searchInPath(QString executable) const
             return fi.absoluteFilePath();
         }
     }
-    return QString::null;
+    return QString();
 }
 
 QStringList Environment::path() const

src/plugins/projectexplorer/projectexplorer.cpp

@@ -1137,7 +1137,7 @@ void ProjectExplorerPlugin::determineSessionToRestoreAtStartup()
     // We have command line arguments, try to find a session in them
     QStringList arguments = ExtensionSystem::PluginManager::instance()->arguments();
     // Default to no session loading
-    d->m_sessionToRestoreAtStartup = QString::null;
+    d->m_sessionToRestoreAtStartup.clear();
     foreach (const QString &arg, arguments) {
         if (sessions.contains(arg)) {
             // Session argument
@@ -1295,7 +1295,7 @@ void ProjectExplorerPlugin::buildQueueFinished(bool success)
             d->m_buildManager->showTaskWindow();
     }
     d->m_delayedRunConfiguration = 0;
-    d->m_runMode = QString::null;
+    d->m_runMode.clear();
 }
 
 void ProjectExplorerPlugin::setCurrent(Project *project, QString filePath, Node *node)
@@ -1417,7 +1417,7 @@ bool ProjectExplorerPlugin::saveModifiedFiles()
             bool alwaysSave = false;
 
             Core::FileManager *fm = Core::ICore::instance()->fileManager();
-            fm->saveModifiedFiles(filesToSave, &cancelled, QString::null,
+            fm->saveModifiedFiles(filesToSave, &cancelled, QString(),
                                   "Always save files before build", &alwaysSave);
 
             if (cancelled)

src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.cpp

@@ -471,7 +471,7 @@ void MaemoRunConfiguration::updateTarget()
     if (m_cachedTargetInformationValid)
         return;
 
-    m_executable = QString::null;
+    m_executable.clear();
     m_cachedTargetInformationValid = true;
 
     Qt4TargetInformation info = qt4Project()->targetInformation(qt4Project()->activeQt4BuildConfiguration(),

src/plugins/qt4projectmanager/qt-maemo/maemoruncontrol.cpp

@@ -152,7 +152,8 @@ void AbstractMaemoRunControl::deploy()
 
         QStringList cmdArgs;
         cmdArgs << "-P" << sshPort() << options() << deployable.fileName
-            << (devConfig.uname + "@" + devConfig.host + ":" + remoteDir());
+            << (devConfig.uname + QLatin1Char('@') + devConfig.host +
+                QLatin1Char(':') + remoteDir());
         deployProcess.setWorkingDirectory(deployable.dir);
 
         deployProcess.start(runConfig->scpCmd(), cmdArgs);
@@ -473,7 +474,7 @@ MaemoDebugRunControl::MaemoDebugRunControl(RunConfiguration *runConfiguration)
     startParams->startMode = Debugger::StartRemote;
     startParams->executable = executableOnHost();
     startParams->remoteChannel
-        = devConfig.host + ":" + QString::number(devConfig.gdbServerPort);
+        = devConfig.host + QLatin1Char(':') + QString::number(devConfig.gdbServerPort);
     startParams->remoteArchitecture = "arm";
     startParams->sysRoot = runConfig->sysRoot();
     startParams->toolChainType = ToolChain::GCC_MAEMO;

src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.cpp

@@ -345,10 +345,10 @@ void S60DeviceRunConfiguration::updateTarget()
                     tr("Could not parse %1. The QtS60 Device run configuration %2 can not be started.")
                     .arg(m_proFilePath).arg(displayName()));
         }
-        m_targetName = QString::null;
+        m_targetName.clear();
-        m_baseFileName = QString::null;
+        m_baseFileName.clear();
-        m_packageTemplateFileName = QString::null;
+        m_packageTemplateFileName.clear();
-        m_platform = QString::null;
+        m_platform.clear();
         m_cachedTargetInformationValid = true;
         emit targetInformationChanged();
         return;

src/plugins/qt4projectmanager/qt-s60/s60devices.cpp

@@ -243,7 +243,7 @@ bool S60Devices::detectQtForDevices()
             continue;
         QFile qtDll(QString("%1/epoc32/release/winscw/udeb/QtCore.dll").arg(m_devices.at(i).epocRoot));
         if (!qtDll.exists() || !qtDll.open(QIODevice::ReadOnly)) {
-            m_devices[i].qt = QString();
+            m_devices[i].qt.clear();
             continue;
         }
         QByteArray buffer;

src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.cpp

@@ -167,7 +167,7 @@ void S60EmulatorRunConfiguration::updateTarget()
                     tr("Could not parse %1. The Qt for Symbian emulator run configuration %2 can not be started.")
                     .arg(m_proFilePath).arg(displayName()));
         }
-        m_executable = QString::null;
+        m_executable.clear();
         m_cachedTargetInformationValid = true;
         emit targetInformationChanged();
         return;

src/plugins/qt4projectmanager/qt4buildconfiguration.cpp

@@ -139,11 +139,7 @@ Qt4Project *Qt4BuildConfiguration::qt4Project() const
 
 QString Qt4BuildConfiguration::baseEnvironmentText() const
 {
-    if (useSystemEnvironment())
+    return useSystemEnvironment() ? tr("System Environment") : tr("Clean Environment");
-        return tr("System Environment");
-    else
-        return tr("Clean Environment");
-    return QString::null;
 }
 
 ProjectExplorer::Environment Qt4BuildConfiguration::baseEnvironment() const
@@ -270,7 +266,7 @@ QString Qt4BuildConfiguration::defaultMakeTarget() const
 {
     ToolChain *tc = toolChain();
     if (!tc)
-        return QString::null;
+        return QString();
     const QtVersion::QmakeBuildConfigs buildConfig = qmakeBuildConfiguration();
 
     switch (tc->type()) {
@@ -285,7 +281,7 @@ QString Qt4BuildConfiguration::defaultMakeTarget() const
     default:
         break;
     }
-    return QString::null;
+    return QString();
 }
 
 QtVersion *Qt4BuildConfiguration::qtVersion() const

src/plugins/qt4projectmanager/qt4nodes.cpp

@@ -101,12 +101,12 @@ QString Qt4PriFile::fileName() const
 
 QString Qt4PriFile::defaultPath() const
 {
-    return QString::null;
+    return QString();
 }
 
 QString Qt4PriFile::suggestedFileName() const
 {
-    return QString::null;
+    return QString();
 }
 
 QString Qt4PriFile::mimeType() const

src/plugins/qt4projectmanager/qt4runconfiguration.cpp

@@ -518,7 +518,7 @@ QString Qt4RunConfiguration::baseEnvironmentText() const
         return tr("System Environment");
     else  if (m_baseEnvironmentBase == Qt4RunConfiguration::BuildEnvironmentBase)
         return tr("Build Environment");
-    return QString::null;
+    return QString();
 }
 
 ProjectExplorer::Environment Qt4RunConfiguration::baseEnvironment() const
@@ -561,7 +561,7 @@ void Qt4RunConfiguration::setWorkingDirectory(const QString &wd)
 {
     if (wd.isEmpty()) {
         m_userSetWokingDirectory = false;
-        m_userWorkingDirectory = QString::null;
+        m_userWorkingDirectory.clear();
         emit workingDirectoryChanged(workingDirectory());
     } else {
         m_userSetWokingDirectory = true;
@@ -610,8 +610,8 @@ void Qt4RunConfiguration::updateTarget()
                     tr("Could not parse %1. The Qt4 run configuration %2 can not be started.")
                     .arg(m_proFilePath).arg(displayName()));
         }
-        m_workingDir = QString::null;
+        m_workingDir.clear();
-        m_executable = QString::null;
+        m_executable.clear();
         m_cachedTargetInformationValid = true;
         emit effectiveTargetInformationChanged();
         return;
@@ -632,19 +632,15 @@ void Qt4RunConfiguration::invalidateCachedTargetInformation()
 
 QString Qt4RunConfiguration::dumperLibrary() const
 {
-    QtVersion *version = qt4Project()->activeQt4BuildConfiguration()->qtVersion();
+    if (const QtVersion *version = qt4Project()->activeQt4BuildConfiguration()->qtVersion())
-    if (version)
         return version->debuggingHelperLibrary();
-    else
+    return QString();
-        return QString::null;
 }
 
 QStringList Qt4RunConfiguration::dumperLibraryLocations() const
 {
-    QtVersion *version = qt4Project()->activeQt4BuildConfiguration()->qtVersion();
+    if (const QtVersion *version = qt4Project()->activeQt4BuildConfiguration()->qtVersion())
-    if (version)
         return version->debuggingHelperLibraryLocations();
-    else
     return QStringList();
 }
 

src/plugins/qt4projectmanager/qtversionmanager.cpp

@@ -559,8 +559,7 @@ QtVersion::QtVersion(const QString &qmakeCommand, bool isAutodetected, const QSt
 }
 
 QtVersion::QtVersion()
-    : m_displayName(QString::null),
+    :  m_id(-1),
-    m_id(-1),
     m_isAutodetected(false),
     m_hasDebuggingHelper(false),
     m_toolChainUpToDate(false),
@@ -572,7 +571,7 @@ QtVersion::QtVersion()
     m_hasDemos(false),
     m_hasDocumentation(false)
 {
-    setQMakeCommand(QString::null);
+    setQMakeCommand(QString());
 }
 
 
@@ -666,7 +665,9 @@ void QtVersion::setQMakeCommand(const QString& qmakeCommand)
 #ifdef Q_OS_WIN
     m_qmakeCommand = m_qmakeCommand.toLower();
 #endif
-    m_designerCommand = m_linguistCommand = m_uicCommand = QString::null;
+    m_designerCommand.clear();
+    m_linguistCommand.clear();
+    m_uicCommand.clear();
     m_toolChainUpToDate = false;
     // TODO do i need to optimize this?
     m_versionInfoUpToDate = false;
@@ -676,7 +677,7 @@ void QtVersion::setQMakeCommand(const QString& qmakeCommand)
     if (qmake.exists() && qmake.isExecutable()) {
         m_qtVersionString = DebuggingHelperLibrary::qtVersionForQMake(qmake.absoluteFilePath());
     } else {
-        m_qtVersionString = QString::null;
+        m_qtVersionString.clear();
     }
     updateSourcePath();
 }
@@ -734,7 +735,7 @@ QString QtVersionManager::findQMakeBinaryFromMakefile(const QString &directory)
         }
         makefile.close();
     }
-    return QString::null;
+    return QString();
 }
 
 QtVersion *QtVersionManager::qtVersionForQMakeBinary(const QString &qmakePath)
@@ -1037,13 +1038,13 @@ QString QtVersion::findQtBinary(const QStringList &possibleCommands) const
         if (QFileInfo(fullPath).isFile())
             return QDir::cleanPath(fullPath);
     }
-    return QString::null;
+    return QString();
 }
 
 QString QtVersion::uicCommand() const
 {
     if (!isValid())
-        return QString::null;
+        return QString();
     if (!m_uicCommand.isNull())
         return m_uicCommand;
 #ifdef Q_OS_WIN
@@ -1077,7 +1078,7 @@ static inline QStringList possibleGuiBinaries(const QString &name)
 QString QtVersion::designerCommand() const
 {
     if (!isValid())
-        return QString::null;
+        return QString();
     if (m_designerCommand.isNull())
         m_designerCommand = findQtBinary(possibleGuiBinaries(QLatin1String("designer")));
     return m_designerCommand;
@@ -1086,7 +1087,7 @@ QString QtVersion::designerCommand() const
 QString QtVersion::linguistCommand() const
 {
     if (!isValid())
-        return QString::null;
+        return QString();
     if (m_linguistCommand.isNull())
         m_linguistCommand = findQtBinary(possibleGuiBinaries(QLatin1String("linguist")));
     return m_linguistCommand;
@@ -1369,8 +1370,8 @@ bool QtVersion::isValid() const
 {
     updateVersionInfo();
     return m_id != -1
-            && qmakeCommand() != QString::null
+            && !qmakeCommand().isEmpty()
-            && displayName() != QString::null
+            && !displayName().isEmpty()
             && !m_notInstalled
             && m_versionInfo.contains("QT_INSTALL_BINS");
 }
@@ -1411,7 +1412,7 @@ QString QtVersion::debuggingHelperLibrary() const
 {
     QString qtInstallData = versionInfo().value("QT_INSTALL_DATA");
     if (qtInstallData.isEmpty())
-        return QString::null;
+        return QString();
     return DebuggingHelperLibrary::debuggingHelperLibraryByInstallData(qtInstallData);
 }
 
@@ -1484,7 +1485,7 @@ QString QtVersion::buildDebuggingHelperLibrary()
 {
     QString qtInstallData = versionInfo().value("QT_INSTALL_DATA");
     if (qtInstallData.isEmpty())
-        return QString::null;
+        return QString();
     ProjectExplorer::Environment env = ProjectExplorer::Environment::systemEnvironment();
     addToEnvironment(env);
 

src/plugins/texteditor/icompletioncollector.cpp

@@ -139,7 +139,7 @@ void ICompletionCollector::filter(const QList<TextEditor::CompletionItem> &items
             if (c.isUpper() && !first)
                 keyRegExp += wordContinuation;
             keyRegExp += QRegExp::escape(c.toUpper());
-            keyRegExp += "|";
+            keyRegExp += QLatin1Char('|');
             keyRegExp += QRegExp::escape(c.toLower());
             keyRegExp += QLatin1Char(')');
         } else {